Quite simple: A fan is anyone who either enjoys the product (either watching it, thinking about it, talking about it or anything else), or wants the product to do well from a standpoint of their own entertainment and enjoyment (rather than, say, because of some business interest in it).

A fan is a representive of a certain product they enjoy it enogh to buy the merchandise or just to watch i think a fan is somebody that almost feels like there part of the product because they know about it from every aspect for example. Wrestling to me is more than a show its a way of life i study it i enjoy it and i always have thats a fan

Support the business in any way you can. Go to a show, order a Pay-Per-View, watch it on TV, watch it online or buy a DVD. If you're a true fan of something you'll go out of your way to check things out.