How long was the turnaround between submitting to betali.st and getting featured? I've heard some people submit just a few days before going live, so by the time users get invites it's still fresh in their minds.
I think it was around 3 months so it wasn't as fresh but what I did was go through email addresses one by one, picked out the companies that sounded the most promising and opened up a dialogue to get those guys in early.
Then kept the other guys informed to try and keep them excited. Although if I would have done it just before launching I would have saved a lot of effort.