In Interlego, applicants sought to register the mark MEGO for “children’s toys, namely, action figures, vehicles, dolls and accessories therefore [sic].” The application was opposed on the basis of prior registration and use of the trademark LEGO and that contemporaneous use of MEGO and LEGO on toys would likely cause confusion, mistake or deception pursuant to Section 2(d) of the Trademark Act. Priority was not a disputed issue.

The Board began its likelihood of confusion analysis by considering the similarities of the goods and the marks. The Board initially held that the goods were, at least in part, legally identical. It then considered the marks, noting that the degree of similarity needed to find likely confusion was not great since the goods were identical in part. The Board further held that the marks LEGO and MEGO were extremely similar, differing only by one letter. The Board viewed as significant the fact that many purchasers of toys are children, who would not be likely to notice this minor difference in the marks.

Applicants presented evidence that the mark MEGO was inspired by the fact that many years ago, their chairman's little brother, wanting to go on a trip with his family, would state, “Me go too. Me go too.” Thus, they argued that their mark differed from the LEGO mark in connotation and pronunciation. The Board rejected these arguments, because consumers would not know the derivation of the applicants’ mark. Moreover, applicants had not educated the public to pronounce their mark as “me go” and, even if they had, the Board found it likely that a significant portion of the public would still pronounce applicants’ mark as “Meg O,” particularly because of the fame of opposers’ LEGO mark. Thus, the Board held that there was a “strong likelihood of confusion” resulting from the contemporaneous use of LEGO and MEGO on toys.

Lastly, the Board held that, if there were any doubt on whether confusion was likely, the Board would resolve any such doubt in opposer’s favor by virtue of the fame of the LEGO mark. The Board observed that LEGO is one of the most famous toy brands and that famous trademarks enjoy a “very broad scope of protection.” Opposer established that LEGO was “very famous” through testimony demonstrating over the last ten years advertising expenses of over $100 million and sales in excess of $1 billion. In addition, market studies demonstrated that approximately two-thirds of United States households with children fourteen years of age and younger owned at least one LEGO toy.