Here is the biggest pay per click programs list where i have listed only the company names which you can later search  them to know their right URL’s.

* adagency1
* AdBrite
* Adhearus
* Adify
* Adsense
* Advertising.com
* AffiliateSensor
* AllFeeds
* AzoogleAds
* BidClix
* Bidvertiser
* Buds Media Network
* Burst Media
* Casale Media
* Chitika
* Claxon
* Clickcent
* Clicksor
* ClickThruTraffic
* ClixGalore
* contextWeb ContextAd
* CoverClicks
* DynamiContext
* Enhance Interactive
* Fastclick
* Hurricane Digital Media
* MIVA AdRevenue Xpress
* Kanoodle Bright Ads
* Mamma Media Solutions
* MarketBanker
* Nixie
* OutBout Media
* Quigo AdSonar
* RealCast Media
* RealTechNetwork
* Revenue Pilot
* Revenue Science
* Right Media
* Rydium
* Searchfeed
* TargetFirst
* TargetPoint
* Traffic Marketplace
* Tribal Fusion
* ValueClick
* Veoda
* Vibrant Media IntelliTXT
* Vibrant Media SmartAd
* Yahoo Publisher Network