I'll be darned, RVBuddy. I didn't know about that link, but it works. I always used
http://www.passportamerica.com , which takes you to a different page, but for the same Passport America.
Passport America is not really a club. It's a discount program. PA signed up 1200 rv parks around the country who agree to give 50% discounts on their rates. Most have some kind of restrictions, like 1 night only, or up to 3 nights, or "not on race weekends" or "not on holiday weekends", or only from September thru April.
Some have no restrictions. Out near Yosemite National Park we stayed in a park where we got the 50% off for our entire two week stay. I believe Glenn and Lorraine recently got 50% off on a 6-night stay in Florida.
These parks run the gamut from excellent parks to the pits. We've been in some that are very, very nice and we've seen some we would not stay in more than one night.
I think the annual fee is $40, or maybe $44 now. We found we recoup our fee in the first month of travel. It only takes 3 or 4 nights to save that much.
We also belong to Good Sam and Escapees, as well as Passport America. I find there are many parks that give all three discounts. Not at the same time, of course. PA gives the most discount (50%) so I check their directory first. If nothing where I want to be, then I check Escapees (15% discount although there are some super dry camping rates here), then Good Sam (10%). All three have paper directories as well as the online directories. Good Sam discounts are indicated in the Trailer Life directory rather than having a separate directory. You have to buy that one.
We also belong to KOA's discount program (10%) but we find only a few KOA's we like and their prices seem to start too high so I'm going to let that one expire when it runs out next January.
If you have more questions, don't hesitate. Maybe some others can jump in and add more information.
If you are a weekender/vacationer, PA may not pay for itself unless you find a park for your vacation that will give you the discount for your entire stay. If fulltiming or extended trips, then there's a good chance it would be a good deal for you.