Blockbuster's online service is just as good (or, at least, nearly as good) as Netflix. They don't have quite as many titles, but I've found them to be faster.
They're (probably) going out of business, though, so Netflix must be getting flooded with new customers jumping ship before it goes down.
Blockbuster has gotten pathetic over the past year. They have long been accused of taking their time with shipments to customers who have a fast turn-around time (which is true in my case). Plus, they started counting the free store rentals I took home in exchange for the mailed ones in the "at home" section, which further slowed the process.
In December, they began to advertise "unlimited" free in-store returns (above the usual 5 per month), which they extended until March. But they got around this by taking two weeks to ship available dvds from my queue, even when I had nothing "at home". I guess Blockbuster finally realized that charging $21.99 per month, with 5 free in store exchanges worth $5.25 each - they were losing money. I sure got a "free ride" for a number of years.
After three separate occasions of waiting two weeks, and a number of unanswered email complaints, I quit my membership.