This appeal challenges the district court’s grant of a preliminary injunction prohibiting defendants-appellants from selling or distributing a book entitled “SUGAR BUST For Life!” as infringing plaintiff-appellee’s federally registered service mark, “SUGARBUSTERS.” Plaintiff-appellee is an assignee of a registered “SUGARBUSTERS” service mark and the author of a best-selling diet book entitled *262 “SUGAR BUSTERS! Cut Sugar to Trim Fat.” We determine that the assignment of the registered “SUGARBUSTERS” service mark to plaintiff-appellee was in gross and was therefore invalid, and we vacate the injunction. However, because plaintiff-appellee might still obtain protection for its book title from unfair competition under § 43(a) of the Lanham Act, 15 U.S.C. § 1125(a), we remand to the district court to consider plaintiff-appellee’s unfair competition claims.
I. FACTUAL AND PROCEDURAL HISTORY
Plaintiff-appellee Sugar Busters, L.L.C. (plaintiff) is a limited liability company organized by three doctors and H. Leighton Steward, a former chief executive officer of a large energy corporation, who co-authored and published a book entitled “SUGAR BUSTERS! Cut Sugar to Trim Fat” in 1995. In “SUGAR BUSTERS! Cut Sugar to Trim Fat,” the authors recommend a diet plan based on the role of insulin in obesity and cardiovascular disease. The authors’ premise is that reduced consumption of insulin-producing food, such as carbohydrates and other sugars, leads to weight loss and a more healthy lifestyle. The 1995 publication of “SUGAR BUSTERS! Cut Sugar to Trim Fat” sold over 210,000 copies, and in May 1998 a second edition was released. The second edition has sold over 800,000 copies and remains a bestseller.
Defendant-appellant Ellen Brennan was an independent consultant employed by plaintiff to assist with the sales, publishing, and marketing of the 1995 edition. In addition, Ellen Brennan wrote a foreword in the 1995 edition endorsing the diet plan, stating that the plan “has proven to be an effective and easy means of weight loss” for herself and for her friends and family. During her employment with plaintiff, Ellen Brennan and Steward agreed to coauthor a cookbook based on the “SUGAR BUSTERS!” lifestyle. Steward had obtained plaintiffs permission to independently produce such a cookbook, which he proposed entitling “Sugar Busting is Easy.” Plaintiff reconsidered its decision in December 1997, however, and determined that its partners should not engage in independent projects. Steward then encouraged Ellen Brennan to proceed with the cookbook on her own, and told her that she could “snuggle up next to our book, because you can rightly claim you were a consultant to Sugar Busters!”
Ellen Brennan and defendant-appellant Theodore Brennan then co-authored “SUGAR BUST For Life!,” which was published by defendant-appellant Shamrock Publishing, Inc. in May 1998. “SUGAR BUST For Life” states on its cover that it is a “cookbook and companion guide by the famous family of good food,” and that Ellen Brennan was “Consultant, Editor, Publisher, [and] Sales and Marketing Director for the original, best-selling ‘Sugar Busters!TM Cut Sugar to Trim Fat.’ ” The cover states that the book contains over 400 recipes for “weight loss, energy, diabetes and cholesterol control and an easy, healthful lifestyle.” Approximately 110,000 copies of “SUGAR BUST For Life!” were sold between its release and September 1998.
Plaintiff filed this suit in the United States District Court for the Eastern District of Louisiana on May 26, 1998, asserting causes of action for trademark infringement and dilution under 15 U.S.C. §§ 1114 and 1125(c), unfair competition and trade dress infringement under § 43(a) of the Lanham Act, 15 U.S.C. § 1125(a), and trademark dilution, misrepresentation, unfair competition and misappropriation of trade secrets under Louisiana state law. Plaintiff sought to enjoin defendants-appellants Ellen Brennan, Theodore Brennan and Shamrock Publishing, Inc. (collectively, defendants) from selling, displaying, advertising or distributing “SUGAR BUST For Life!,” to destroy all copies of the cookbook, and to recover damages and any profits derived from the cookbook.
*263 The mark that is the subject of plaintiffs infringement claim is a service mark that was registered in 1992 by Sugarbus-ters, Inc.,, an Indiana corporation operating a retail store named “Sugarbusters” in Indianapolis that provides products and information for diabetics. The “SUGAR-BUSTERS” service mark, registration number 1,684,769, is for “retail store services featuring products and supplies for diabetic people; namely, medical supplies, medical equipment, food products, informational literature and wearing apparel featuring a message regarding diabetes.” Sugarbusters, Inc. sold “any and all rights to the mark” to Thornton-Sahoo, Inc. on December 19, 1997, and Thornton-Sahoo, Inc. sold these rights to Elliott Company, Inc. (Elliott) on January 9, 1998. Plaintiff obtained the service mark from Elliott pursuant to a “servicemark purchase agreement” dated January 26, 1998. Under the terms of that agreement, plaintiff purchased “all the interests [Elliott] owns” in the mark and “the goodwill of all business connected with the use of and symbolized by” the mark. Furthermore, Elliott agreed that it “will cease all use of the [m]ark, [n]ame and [trademark [interests within one hundred eighty (180) days.”
In support of its request for a preliminary injunction, plaintiff argued to the district court that the recipes in the cookbook did not comport with the “SUGAR BUSTERS!” lifestyle and that consumers were being misled into believing that defendants’ cookbook was affiliated with, or otherwise approved by, plaintiff. Plaintiff asserted that even if its purported service mark is found invalid, plaintiff is still entitled to a preliminary injunction under § 43(a) of the Lanham Act because its title “SUGAR BUSTERS! Cut Sugar to Trim Fat!” has developed a “secondary meaning” in the minds of customers, plaintiff has developed a common law service mark through the seminars it holds regarding the “SUGAR BUSTERS!” lifestyle, and defendants infringed plaintiffs trade dress.
Defendants argued to the district court that plaintiffs service mark is invalid because: (1) it was purchased “in gross,” (2) the term “SUGARBUSTERS” has become generic through third-party use, and (3) plaintiff abandoned the mark by licensing it back to Elliott without any supervision or control over the retail store in Indiana that continues to operate under the “Su-garbusters” name. Defendants argued that, even if the service mark is valid, their cookbook could not infringe it because the mark is limited to a retail store and a trademark may not be obtained for a book title. Finally, defendants asserted that their use of the title was a “fair use” and that plaintiff is not entitled to an injunction under equitable principles because Stewart breached his agreement with Ellen Brennan and invited her to write the cookbook that is now the subject of this case.
The district court heard evidence relating to the preliminary injunction for three days beginning on June 30, 1998 and entered a preliminary injunction on September 22, 1998 that prohibits defendants from engaging in the sale and distribution of their cookbook, “SUGAR BUST For Life!”
See Sugar Busters, L.L.C. v. Brennan,
[t]he plaintiff has used the trademark to disseminate information through its books, seminars, the Internet, and the cover of plaintiffs recent book, which reads “Help Treat Diabetes and Other Diseases.” Moreover, the plaintiff is moving forward to market and sell its own products and services, which comport with the products and services sold by the Indiana corporation. There has been a full and complete transfer of the *264 good will related to the mark, and the plaintiff has licensed the Indiana corporation to use the mark for only six months to enable it to wind down its operations.
Id.
The district court then considered whether defendants’ use of the mark “ ‘creates a likelihood of confusion in the minds of potential customers as to the source, affiliation, or sponsorship’ ” of the cookbook using the factors we outlined in
Elvis Presley Enterprises, Inc. v. Capece,
The district court found that “plaintiff has established that there is a likelihood of confusion in the minds of customers,” that there is a substantial threat plaintiff will suffer irreparable injury without a preliminary injunction, that this threatened injury outweighs any damage that an injunction may cause defendants, and that an injunction will not disserve the public interest. Id. at 1516. The court refused to consider defendants’ fair-use argument because it was raised for the first time in defendants’ post-hearing brief, found defendants’ equitable argument insufficient to prevent an injunction, and enjoined defendants from engaging in the sale and distribution of “SUGAR BUST For Life!” See id. at 1517. Because the district court entered the injunction based on plaintiffs trademark infringement claim, the court declined to analyze or discuss plaintiffs remaining claims. See id. at 1516. Defendants timely appeal.
II. DISCUSSION
Defendants argue that the district court erroneously concluded that plaintiffs purported service mark in “SUGARBUS-TERS” is valid and that their cookbook infringes the mark. Defendants also argue that plaintiffs unfair competition claims under § 43(a) of the Lanham Act fail because that section cannot protect a single book title or, alternatively, that remand is necessary because the district court did not consider whether the book title has acquired secondary meaning. Defendants assert that remand is also necessary on plaintiffs claim that it has an unregistered service mark in “SUGAR BUSTERS!” as a result of the seminars it held promoting the book because the district court did not consider this argument or make any factual finding regarding likelihood of confusion. Finally, defendants argue that the district court erred by rejecting their arguments regarding fair use and equitable principles. We address each of these arguments in turn. 2
A. Standard of Review
We review a district court’s ultimate decision to grant a preliminary injunction for an abuse of discretion.
See Affiliated Prof. Home Health Care Agency v. Shalala,
B. Plaintiffs Registered Service Mark
A trademark is merely a symbol of goodwill and has no independent significance apart from the goodwill that it symbolizes.
See Marshak v. Green,
The purpose of the rule prohibiting the sale or assignment of a trademark in gross is to prevent a consumer from being misled or confused as to the source and nature of the goods or services that he or she acquires.
See Visa, U.S.A., Inc. v. Birmingham Trust Nat’l Bank,
Plaintiffs purported service mark in “SUGARBUSTERS” is valid only if plaintiff also acquired the goodwill that accompanies the mark; that is, “the portion of the business or service with which the mark is associated.”
Id.
Defendants claim that the transfer of the “SUGAR-BUSTERS” mark to plaintiff was in gross because “[n]one of the assignor’s underlying business, including its inventory, customer lists, or other assets, were transferred to [plaintiff].” Defendants’ view of goodwill, however, is too narrow. Plaintiff may obtain a valid trademark without purchasing any physical or tangible assets of the retail store in Indiana — “the transfer of goodwill requires only that the services be sufficiently similar to prevent consumers of the service offered under the mark from being misled from established associations with the mark.”
Id.
at 1376 (internal quotation marks omitted);
see Marshak,
The district court found, without expressly stating the applicable legal standard, that “[t]here has been a full and complete transfer of the good will related to the mark.”
Sugar Busters,
In concluding that goodwill was transferred, the district court relied in part on its finding that the mark at issue is registered in International Class 16, “information, literature, and books.” However, the registration certificate issued by the United States Patent and Trademark Office states that the service mark is “in class 42” and is “for retail store services featuring products and supplies for diabetic people.”
Id.
The district court also relied on its finding that “plaintiff is moving forward to market and sell its own products and services, which comport with the products and services sold by the Indiana corporation.”
Id.
Steward testified, however, that plaintiff does not have any plans to operate a retail store, and plaintiff offered no evidence suggesting that it intends to market directly to consumers any goods it licenses to carry the “SUGAR BUSTERS!” name. Finally, we are unconvinced by plaintiffs argument that, by stating on the cover of its diet book that it may “[h]elp treat diabetes and other diseases” and then selling some of those books on the Internet, plaintiff provides a service substantially similar to a retail store that provides diabetic supplies.
See PepsiCo,
C. Unfair Competition Claims
Plaintiff argues that we must still uphold the preliminary injunction because it has demonstrated a likelihood of success on the merits of its claims under § 43(a) of the Lanham Act.
5
The Supreme Court has recognized that § 43(a) “‘prohibits a broader range of practices than does § 32,’ which applies to registered marks,” and that § 43(a) protects qualifying unregistered marks.
Two Pesos, Inc. v. Taco Cabana, Inc., 505
U.S. 763, 768,
1. Plaintiffs Book Title
As a preliminary matter, we must consider defendants’ contention that a book title may not receive protection under § 43(a). Defendants contend that “titles of single literary works are not registerable” as trademarks, and therefore that § 43(a) cannot protect plaintiffs title because the Supreme Court has held “that the general principles qualifying a mark for registration under § 2 of the Lanham Act are for the most part applicable in determining whether an unregistered mark is entitled to protection under § 43(a).”
Id.; see Thompson Med. Co. v. Pfizer Inc.,
In order to be registered as a trademark, a mark must be capable of
*268
distinguishing the applicant’s goods from those of others.
See
15 U.S.C. § 1052;
Two
Pesos,
Over forty years ago, the Court of Customs and Patent Appeals (the predecessor to the current Federal Circuit) considered whether the title of a single book may be the subject of a trademark.
See In re Cooper,
The purchaser of a book is not asking for a “kind” or “make” of book. He is pointing out which one out of millions of distinct titles he wants, designating the book by its name. It is just as though one walked into a grocery store and said “I want some food” and in response to the question “What kind of food?” said, “A can of chicken noodle soup.”
Id.
at 614-15;
see also International Film Serv. Co. v. Associated Producers, Inc.,
The descriptive nature of a literary title does not mean, however, that such a title cannot receive protection under § 43(a). In fact, the
Cooper
decision itself recognized that “[i]t is well known that the rights in book titles are afforded appropriate protection under the law of unfair competition.”
Plaintiff must demonstrate a high degree of proof to establish secondary meaning.
8
See Vision Ctr. v. Opticks, Inc.,
Plaintiff asserts that the record is “replete with evidence sufficient to support a ruling [on secondary meaning] by this
*270
[c]ourt,” including evidence that plaintiff sold over 210,000 copies of its book prior to May 1998, received unsolicited media coverage, used the title exclusively for thirty months, and was intentionally copied by defendants.
9
Furthermore, plaintiff argues that the district court found secondary meaning in plaintiffs book title when it stated that it “finds that the trademark, SUGARBUSTERS, has gained strength, not only locally, but nationally due to its use in conjunction with the success of the book.”
Sugar Busters,
2. Plaintiffs Seminars
Plaintiff argues that the preliminary injunction should also be upheld under § 43(a) because defendants’ book title violates its common law service mark in seminars that it held promoting “SUGAR BUSTERS! Cut Sugar to Trim Fat.” Specifically, plaintiff alleges that it has held over one hundred seminars regarding the “SUGAR BUSTERS!” lifestyle since the fall of 1995 and that defendants’ book title should be enjoined because it is likely to cause confusion with respect to these seminars.
The district court did not consider plaintiffs argument regarding these alleged seminars and made no factual findings on this issue. We therefore remand plaintiffs claim to the district court so that it may properly determine whether plaintiff used such a mark with these seminars and whether such use was generic, descriptive, suggestive, arbitrary or fanciful. If the district court determines that such use is protectable under § 43(a), the court should determine whether plaintiff has demonstrated “particularly compelling” evidence indicating that consumers are likely to confuse the title of defendants’ book with such a mark.
See Twin Peaks Prod., Inc. v. Publications Int’l, Ltd.,
D. Fair Use
Defendants argue that plaintiff cannot prevail on its § 43(a) claims because defendants’ use of their book title “SUGAR BUST For Life!” is protected by the fair-use doctrine.
See Soweco, Inc. v. Shell Oil Co.,
The district court declined to consider defendants’ fair-use argument, stating that it was raised for the first time in defendants’ post-hearing brief.
See Sugar Busters,
E. Equitable Considerations
Defendants’ final argument is that plaintiff is not entitled to a preliminary injunction under principles of equity. See 15 U.S.C. § 1116(a) (“The several courts vested with jurisdiction of civil actions arising under this chapter shall have power to grant injunctions, according to the principles of equity and upon such terms as the court may deem reasonable, to prevent ... a violation under section 1125(a) of this title.”). Defendants assert that plaintiff engaged in inequitable conduct because Steward breached an agreement with Ellen Brennan to co-author a cookbook, Steward invited Ellen Brennan to “snuggle up” to plaintiffs book, plaintiff terminated Ellen Brennan’s employment after she retained counsel, and plaintiff refused to abide by a purported settlement of the claims at issue in this case.
The district court found that defendants’ asserted “equitable considerations based on the arguments of ‘inequitable behavior’ and ‘improper purpose’ are inadequate to present a defense based on equitable relief.”
Sugar Busters,
III. CONCLUSION
For the foregoing reasons, we VACATE the preliminary injunction and REMAND to the district court for further proceedings consistent with this opinion.
Notes
. The nonexhaustive list of factors relevant to determining the likelihood of confusion that we enunciated in
Elvis Presley Enterprises
is as follows: (1) the type of trademark allegedly infringed, (2) the similarity between the marks, (3) the similarity of the products or services, (4) the identity of the retail outlets and purchasers, (5) the identity of the advertising media used, (6) the defendant’s intent, and (7) any evidence of actual confusion.
See
. Defendants also argue that the district court committed reversible error by entering a preliminary injunction without considering whether to impose a bond on plaintiff.
See
Fed.R.Civ.P. 65(c) ("No restraining order or preliminary injunction shall issue except upon the giving of security by the applicant, in such sum as the court deems proper, for the payment of such costs and damages as may be incurred or suffered by any party who is found to have been wrongly enjoined or restrained.”);
Phillips v. Chas. Schreiner Bank,
. Plaintiff argues that we should affirm the district court's preliminary injunction based on its unfair competition claims under § 43(a) if its trademark infringement claim fails. Specifically, plaintiff argues that defendants’ book title is likely to cause confusion with respect to plaintiff's book title and with seminars that plaintiff held promoting its book. Plaintiff does not raise, and we do not consider, its trademark dilution, trade-dress infringement, or state-law claims as alternative bases supporting the preliminary injunction.
. Defendants also argue that plaintiffs purported service mark is invalid because plaintiff offered no evidence demonstrating the validity of the purported assignment from Sugarbusters, Inc. to Thornton-Sahoo, Inc., or Thornton-Sahoo’s subsequent assignment to Elliott, and because plaintiff licensed the mark back to Elliott without retaining any supervision or control.
See Exxon Corp. v. Oxxford Clothes, Inc.,
. Under § 43(a),
Any person who, on or in connection with any goods or services ... uses in commerce any word, term, name, symbol, or device, or any combination thereof, or any false designation of origin, false or misleading description of fact, which ... is likely to cause confusion, or to cause mistake, or to deceive as to the affiliation, connection, or association of such person with another person, or as to the origin, sponsorship, or approval of his or her goods, services, or commercial activities by another person ... shall be liable in a civil action by any person who believes that he or she is or is likely to be damaged by such act.
15U.S.C. § 1125(a).
. In their initial appellate brief, defendants state that the term "Sugar Busters” for a diet book title has become generic and is therefore not entitled to any trademark protection. However, in their reply brief, defendants argue that no portion of the district court’s opinion "address[es] the genericness issue which has been raised by the Brennans-— namely, that the unregistered term 'Sugar Busters'
for a diet
has become generic.” Indeed, defendants argued to the district court that the term "Sugar Busters” is generic for a diet and introduced evidence of a survey where participants supplied "Sugar Busters” as a name for a diet "based upon cutting back on foods high in sugar content,” but did not argue that plaintiff's book title, "SUGAR BUSTERS! Cut Sugar to Trim Fat,” is generic.
See Soweco, Inc. v. Shell Oil Co.,
. Any finding that defendants’ book title is likely to cause confusion with plaintiff's book title must be “particularly compelling” to outweigh defendants' First Amendment interest in choosing an appropriate book title for their work.
Twin Peaks Prods., Inc. v. Publications Int’l, Ltd.,
. Plaintiff must show that its title "SUGAR BUSTERS! Cut Sugar to Trim Fat” had developed secondary meaning at the time that defendants allegedly violated § 43(a) by releasing their book, "SUGAR BUST For Life!”
See Braun Inc. v. Dynamics Corp.,
. Plaintiff also stated at oral argument that "[tjhere is a very good survey in [the record] done by a professional pollster for [plaintiff] to show that this secondary meaning exists." The survey, which was performed at a Louisiana shopping mall in June 1998, asked some respondents whether they had ever heard the name "SUGARBUSTERS!,” others whether they had ever heard the name "SUGAR BUST," and asked all respondents whether they thought of "a special enzyme, a diet plan, a low calorie sweetener or something else" when they heard these names. We fail to see how this survey suggests whether consumers associate the title "SUGAR BUSTERS! Cut Sugar to Trim Fat” with plaintiff or its book.
