You can use classified ads to drive means of advertising directly to your website. I have enlisted some of my favorite ads sites.
Craiglist.com
Trovit.com
Backpage.com
Inetgiant.com
Adpost.com
Classifiedforfree.com
Backpage.com
Gumtree.com
Oodle.com
Usfreeads.com
Freeclassifiedstuff.com
Yakaz.com
Epage.com
Recycler.com
Webcosmo.com
Hobbly.com
Olx.com