I have been using ad posting for traffic for a while now! It had a good side effect I didn't expect, it raised my page rank and now I get more hits from search engines. I use these sites for posting Company Advertising Classifieds PR 2 Craigslist PR 8 Kijiji PR 7 These sites work great for marketing and for PR! Use them all!
How and where do you post your ads without them getting deleted? Craigslist is notorious for deleting ads with links in them...unless you can post ads with links in a particular section that I'm not aware of...