It's no more legitimate than Suprnova/Kazaa is, ie: they're going to take your money and send you a program that connects to a free p2p network, probably kazaa.
So it's still illegal to download the stuff, you're just paying to access something you could access for free elsewhere. Don't give your credit card to these scam artists.
If you want to pay for movies, try Blockbuster Online. $15/mo, 3 DVDs out at a time, plus two free in-store rental coupons. I've gotten at least 9 DVDs in the last month, I've lost count. That doesn't include the two rentals I got from the local store.
Netflix has the same thing, only it's more per month and you don't get any in-store rentals.