Comic-Con as a show has grown so much in the past decade. Things like comic books and cards are getting pushed aside for TV, Movies and Video Games. One look at the floor shows who has the money (Hollywood, tech companies) to put up the mega booths with glitz and sound. Heck, even the once great Marvel Comics has scaled back their booth. Topps probably figures it is not worth the money, time, etc. to try and get any notice in San Diego at this point.