I joined because we were going to WDW and I knew we'd eat at RFC at least once, plus we like to hit the one at Woodfield Mall when we make our yearly shopping trek to Chicago. It costs $15 to join and you then receive a $10 gift certificate (so basically it costs $5). It's good for either 10% off or a free appetizer (you don't usually get to choose which app) at all Landry's restaurants: RFC, Landry's Seafood, Joe's Crab Shack, etc (there are many locations). It's also good for 10% off in the gift shop and you also get immediate seating (instead of having to wait for your name to be called you get to go right up to the line at the fish tank arch). So basically the first time you use it you've gotten your $5 back! Most of the RFC's I've been in give you an app choice of the quesadillas, the wierd dip stuff, and something else (can't remember). Sometimes you don't get a choice (info actually says "chef's app of the day). At our local Joe's Crab Shack it depends too: sometimes we have no choice at all and sometimes we can get any appetizer.
Also, the card never expires or needs to be renewed and they send you things in the mail like a $5 gift cert on your birthday or a postcard for a free volcano (the most recent of which had already expired before I received it).