Wanted to mention that I did my first Shopkick redemption today. Truthfully, I thought that this would be the weakest of the three programs that I had listed, but it has turned out quite nicely. I redeemed 2,500 points today for a $10 Starbucks gift card.
One of the reasons that I thought that the program would die was an inability to monetize users. They seem to have gotten around that, however, by allowing you to link your credit card and earn "kicks" in stores (for those of us who still do some off-line shopping). It's not huge, but it does generate some revenue for them. I earned my first in-store kicks at the Disney Store the other day, but there are a bunch of others. While there are a number of rebate sites for on-line shopping, this is the first one outside of iDine that will get you points in stores.