Pay Per Click Marketing (PPC) is a Search Engine Marketing advertising medium where advertisers bid on relevant keywords or phrases. These keywords or search phrases are used primarily on the major search engines including Google, Yahoo and MSN but also on advertising networks, directories, online periodicals, content-specific websites and blogs. A PPC advertiser only pays when the person performing a search clicks on an ad. After clicking on the ad, the visitor is immediately directed to the advertiser's website or landing page.

Search Engines are divided into a First Tier and Second Tier ranking:

• First Tier: Google (AdWords), Yahoo (Search Marketing) & Microsoft MSN/LIVE
• Second Tier: Ask, LookSmart, Miva Business.com, 7Search, Kanoodle, Search123, Verizon Superpages and many others.