A Psuedo-Fan is a person who jumps on whatever thing happens to be the latest thing. They act as if they have been fans for their entire life, and claim to be extremely knowedgeable about their new fandom. They wear the merchandise, buy the games (if any), watch the movies, etc. Once the hype has died down, they go to the next popular thing.
They are EXTREMELY irritating to Proper-Fans, who consider them a mockery to the fandom.
After watching the 2009 Transformers movie, Jill went on a Transformers merchandise shopping spree, spending over five hundred dollars to keep up with the hype.
After seeing the trailer for the next Harry Potter Movie, Jill threw away all her Transformers stuff and spent another five hundred dollars getting Harry Potter stuff.
Etc, etc, etc, continuing on in her Psuedo-Fan existence.