PPC
Stands for pay-per-click and means the same as cost-per-click.
Paid Listings
Listings that search engines sell to advertisers, usually through paid placement or paid inclusion programs. In contrast, organic listings are not sold.
Pay-for-Performance
Term popularized by some search engines as a synonym for pay-per-click, stressing to advertisers that they are only paying for ads that “perform” in terms of delivering traffic, as opposed to CPM-based ads, where ads cost money, even if they don’t generate a click.
Paid Placement
Advertising program where listings are guaranteed to appear in response to particular search terms, with higher ranking typically obtained by paying more than other advertisers. Paid placement listings can be purchased from a portal or a search network. Search networks are often set up in an auction environment where keywords and phrases are associated with a cost-per-click (CPC) fee. Overture and Google are the largest networks, but MSN and other portals sometimes sell paid placement listings directly as well. Portal sponsorships are also a type of paid placement.