Mostly free sites for advertising  and  Links for earning credits on traffic exchangers..Ive taken the time and effort to test them all including the pay ones
And am sharing these with you for free.

http://www.optinmarketing.biz   ---------------------Not Free, but great results

http://www.websitevisitors.biz   -------------------- Not Free , but great results

http://viralurl.com/funkymover/advertiser/                    ----------- Free page advertiser

http://viralurl.com/funkymover/freeadvertisor/                ----------- Free page advertiser
   
http://viralurl.com/funkymover/freeadvertisor2/               ----------- Free page advertiser

http://viralurl.com/funkymover/freeadvertisingforum/          ----------- Free forum advertiser

http://viralurl.com/funkymover/freeadforum/                   ----------- Free forum advertiser

http://viralurl.com/funkymover/freeurladvertiser/             ----------- Free forum advertiser& Url submitter

http://viralurl.com/funkymover/sellingads/                    ----------- get paid for every visit to ur site

http://viralurl.com/funkymover/freedirectory/                 ----------- Free advertising directory

http://viralurl.com/funkymover/freedirectory2/                ----------- Free advertising directory

http://viralurl.com/funkymover/faasafemailer/                 ----------  Faa Safemailer (not free)

http://viralurl.com/funkymover/adultexchanger/                ----------- Traffic exchanger (for adult sites)

http://viralurl.com/funkymover/adultexchanger1/               ----------- Traffic exchanger (for adult sites)

http://viralurl.com/funkymover/trafficxchanger1/              ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger2/              ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger3/              ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger4/              ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger5/              ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger6/              ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger7/              ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger8/              ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger9/              ----------- Traffic exchanger

http://viralurl.com/funkymover/traffixchanger10/              ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger11/             ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger12/             ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger13/             ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger14/             ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger15/             ----------- Traffic exchanger

http://viralurl.com/funkymover/trafficxchanger17/             ----------- Traffic exchanger