1. Search / PPC
1.1. The Big Three (err.. Two)
1.1.1. http://google.com/adwords
1.1.2. https://adcenter.microsoft.com
1.2. 2nd Tier
1.2.1. http://miva.com
1.2.2. http://7search.com
1.2.3. https://ads.kanoodle.com
1.2.4. http://www.looksmart.com
1.2.5. http://www.search123.uk.com
1.2.6. http://www.adbrite.com
1.2.7. http://www.bidvertiser.com
1.3. In-Text
1.3.1. http://kontera.com
1.3.2. http://infolinks.com
1.3.3. http://trafficvance.com
2. PPV / CPV
2.1. Top Five
2.1.1. http://www.trafficvance.com
2.1.2. http://www.leadimpact.com
2.1.3. http://mediatraffic.com
2.1.4. http://adonnetwork.com
2.1.5. http://directcpv.com
2.2. 2nd Tier
2.2.1. http://clicksor.com
2.2.2. http://adoori.com
2.2.3. http://findology.com
2.2.4. http://www.jemamedia.com
2.2.5. http://ezanga.com
3. Mobile
3.1. Blind Networks
3.1.1. http://www.mojiva.com
3.1.2. http://inmobi.com
3.1.3. http://www.buzzcity.com
3.1.4. http://www.madvertise.de
3.1.5. http://adfonic.com
3.1.6. http://www.admob.com
3.1.7. http://www.admoda.com
3.2. Premium Blind Networks
3.2.1. http://www.greystripe.com
3.2.2. http://www.millennialmedia.com
3.2.3. http://www.jumptap.com
3.2.4. http://huntmads.com/?lang=en
4. Display / Media Buys
4.1. Self-Serve
4.1.1. http://megaclick.com
4.1.2. http://mochimedia.com
4.1.3. http://sitescout.com
4.1.4. http://pulse360.com
4.1.5. http://www.google.com/displaynetwork
4.1.6. http://www.adperium.com
4.2. http://cpxinteractive.com
4.3. http://adbuyer.com
4.4. http://adengage.com
4.5. http://adblade.com
4.6. http://advertise.com
4.7. http://www.advertising.com
4.8. http://admarketplace.com
4.9. http://www.contextweb.com
4.10. http://adknowledge.com
4.11. http://admanage.com
4.12. http://casalemedia.com
4.13. http://rubiconproject.com
4.14. http://www.valueclickmedia.com
4.15. http://tribalfusion.com
4.16. http://adroll.com
4.17. http://chitika.com
4.18. http://www.traffiq.com
4.19. http://www.burstmedia.com
5. Social
5.1. http://www.facebook.com/advertising
5.2. https://ads.pof.com
5.3. https://www.myads.com
5.4. Twitter
5.4.1. http://sponsoredtweets.com
5.4.2. http://ad.ly
5.4.3. http://izea.com
5.5. App Traffic
5.5.1. http://rockyou.com
5.5.2. http://socialhour.com
5.5.3. http://www.socialmedia.com
5.5.4. http://advertiser.cubics.com