I sign for every program where I stay. My main ones are Priority Club, Best Western, and Hilton. They all build up pretty fast for me. I have signed with others, and occasionaly get enough for a free night or so. It dosent hurt to have a lot of them, if you travel extensively.

I rarely stay at AmericInn, but on my last stay, they sent me $40.00. That's 40 bucks that I wouldn't have if I didn't sign up with them a few years ago.