This is really a question for the Rewards Board, so I'm going to move it there.
I've been a eRewards member for several years but I don't think that the program is very good. The rewards are limited and you can lose some of your rewards dollars due to expiration. Most of the rewards will get you $/$$ and are more like coupons than they are rewards. The Blockbuster coupons can only be used one at a time/once per month...and they expire.
I redeem for HHonors Points, which helps a little towards getting a free stay, but you can only redeem for each type of reward once (maybe twice) a year.