I've been with them for about 1 month and a half now. One of the guys at work had it and absolutely loves it. He gets free coupons in his email every month for free rentals and free previously viewed DVD's at any store. I thought that would be worth it alone so I signed up. The first month I got 2 free rentals in the store and 1 B1G1 previously viewed. The second month, just 2 free rentals. I'm going to wait to see what month #3 brings before I continue. Maybe they give better rewards to those that stay with it longer.
Otherwise, the service is pretty good. I signed up for my account through MyPoints on a Thursday afternoon while I was at work and was shocked to find 3 movies in my mailbox Friday. Monday I sent 2 back and today, 2 more were in the box. I don't like the Queue though- I have movies listed in order and they frequently go out of order when filling them. Not because the movie is not available, I really don't know why. I guess that is why they give you the free in store rentals!!
I guess it's worth a shot- the movies do arrive quickly.