Coincidental to the blurb on Yakult below, I just learned of the Ninth Circuit’s recent case discussing fame, Thane v. Trek, in this case, the fame of the TREK mark used for mountain bikes.  To clarify my comments below, fame is and should be interpreted differently when determining whether there is infringement, or dilution, or whether there is an element of bad faith on the part of defendant.  In this case, where the court is asking whether defendant’s use dilutes plaintiff’s mark, it (properly in my view) adopts a high standard of fame, namely whether the name is known to general public.  Under this standard, a mark which commands 98% of a niche market will not be deemed to be famous.