(Cost Per Action) Networks that pay out based on an "action" -- meaning that a user must sign-up to the offer or perform any other sort of action specified by an advertizer.
(Cost per 1,000 Impressions) Networks that pay out based on a number of exposures of a campaign.
(Cost Per Click) Networks that pay based on a number of times your visitors clicked on the advertizing.
Ad network (4)
A general ad network that supports a variety of types of advertizing campaigns. They will generally provide you with some tools for rotating their ads, and selecting ads that run on your website.
Affiliate Program (2)
A network that has access to product-specific campaigns. The payout is usually a percentage of the revenue generated by merchandize sold on the site.
A network that pays for a number of Pop-Up or Pop-Under windows displayed on the site.
A network that serves standard 468x60 banner campaigns.
An ad network that serves skyscraper (vertical) ads.
Text Links/Ads (4)
A program that pays you for putting simple text links on your pages. Once your visitors click on a link, or on a page that a link leads to, you get paid.
An ad-network that serves interstitial ads. Interstitials are full-screen ads that are displayed for a few seconds before a visitor is being redirected to the target page.
A network that serves rectangle "box" ads (usually, 300x250 or 250x250 pixels in size).