[sevenadrian]

Thanks man!

HelloList can definitely do that (need to make that more obvious), mainly because it's just a simple platform. People sign up and promote it and such, and on the backend you get an ordered list of all the entries including info like who referred them, number of referrals, when they signed up, ordered by their rank (can dl it as a CSV too). Whether you let just the top 100 in your beta for free, give everyone who referred >3 people something, give the top 500 people a "badge", or etc., is entirely up to those building the list.