Ask HN: User base bootstrapping via promoters

In many dating sites, the desirability of joining the site is in many ways simply a function of the number of people on the site. There's been a fair amount of discussion on bootstrapping a user base on HN so far, but I was thinking of a scheme that I have not yet seen around here...

The basic idea is to identify in each region I'm focusing on (e.g., New York, Chicago) a number of "Tier-1" promoters -- people who are well connected, have large numbers of twitter/facebook friends, generally outgoing people-persons. They are given some kind of code, and invite people to the site using that code (can even be certain bloggers, etc..). For everyone that ends up with a paid membership on the site using this person's invitation code, they will get something like $5. Anyone they invite can become a "Tier-2" promoter, and can get something like $5 in credit on the site (or an extra 6 months or year, or something like that). Any thoughts on a scheme like this? Thanks.