I may be the last blogger to write about Plink, mostly because I don't have a lot of experience with it, but in case you have been living under a rock without blogs, here it is. It's actually a pretty good program.
It's also a simple program: They give you a list of participating merchants. You attach your credit card to your plink account (only one card, but I believe you can change it). Whenever you buy something at one of the merchants, they give you points based on how much you spent. The points can be traded in for gift cards, miles, etc. My experience with them has been good. Think of it as the dining for miles type programs, except that it's shopping for points.
Note: You can still get your credit card bonuses in addition to the Plink points. For instance, if you use a Chase Ink card at Staples, you will get your Plink points in addition to 5X UR points.
I really like these programs where there is no downside. And yes, I do receive a referral bonus if you sign up using my link here-I get 100 points, which I think is worth a dollar, which will go a long way toward rounding out my collection of Phineas and Ferb dolls.