Virgin Wine and Wall Street Journal Wine (operated by the same company) both have the same deal: $69 for 15 bottles of wine. I have a couple of friends who are members. The wines I've tasted have been pretty decent.
Think of it like Columbia House Records. If all you ever buy is the initial deal, it's good. And, unlike Columbia House, you can cancel at anytime. But if you don't cancel, they will automatically send you a case of wine every three months and debit your card. You have to specifically let them know you do not want the case.
It's probably great for a lot of people, but personally I like to have more control over purchases. And I just don't like the idea of a case of wine showing up unexpected, should I forget to let them know I don't want a shipment.