I use Blockbuster Online for the sole reason that I signed up six years ago when it was relatively new, and it offered more services than NetFlix. Well, they aren't allowed to raise my monthly fee, so I still pay 20 bucks per month for their unlimited plan, which now goes for $40/month or something outrageous.
I like the fact that I can take my return envelope into the Blockbuster store 5 minutes from my house and get a free movie. Instant gratification. I tend to get 6-10 movies per week which is like twice what I could ever watch, so my dvd ripper and hard drives see a lot of use
Now, things would be different if NetFlix offered every movie for streaming. But since their streaming library is (so far) pretty small, and Blockbuster still gets a lot of new releases a month before NetFlix, I'm sticking with Blockbuster for now.
Hopefully my "grandfather" price plan will stay in effect after Blockbuster is sold...