The obvious things are
- Get quality content
- Optimise every page on your site
One thing you could try is TrafficSwarm - this is a website referral system whereby members visit each other's websites. Effectively you get one visitor for every one site you visit from the panel.
How effective it is in providing "clients" I can't really say; but I have tried it out this weekend and it definitley WORKS in the sense that it provides high targetted visitor numbers.
If you have a spare 10 minutes give it a try - its 100% FREE
There IS a "pro" upgrade but my advice would be that you do the FREE version and upgarde later if it works for you.
TrafficSwarm