It's all about referrals, isn't it?

registering through downline builders is the first thing I consider while joining a new paid site, because in this case I get at least one guaranteed referral who signs up after me in the chain. using traffic exchange programmes is a way to get referrals for free, but it takes a long time to build a huge downline this way.

I suggets you make a blog of your sites and promte it. That's where I get mine from. Takes a little effort to prepare it and set it up but once it's out there refs will arrive. Goodluck!