I disagree. I could see this working over and over if executed well.
Imagine a brand new site called Hulu that promises free TV shows in a legal way. To get on the beta, you do the normal list sign up but they tell you that you could get first access if you referred 3 people. Would you dig out 3 people to refer? My response is "Hell ya!" if I think my friends will like it.
How you get people to want the service bad enough that they'll invite others to get on a priority list will likely be the thing that people will need to focus on.
If you are trying to get 'priority' or early access to the site/service then you have no idea if your friends will like it. You don't even know if you like it yet.
Unfortunately, I foresee many "me too" companies that will make this a tired paradigm.