One of the best ways to be innovative is take something that works in one field and apply it to another. Punchtab aims to do just that; it provides a loyaly program for websites similar to hotels or airlines.
I was able to sign up and setup a reward for my blog in seconds. I was also able to setup rewards very soon e.g., 10000 points = $10 gift card for amazon. What I was able to figure out is how to setup feedback for actions e.g., if someone leaves a comment, how do I make sure that they get points? The only points that get automatically setup are for Facebook shares and likes. Then when I went back to the site, I wasn't able to log in. In summary, seems like an excellent idea, but not executed well so far.