The major search engines offer paid placements that are based on keyword search. Depending on the search engine, these placements may appear at the top of the search results, to the side, or within the search results themselves. Different search engines display a different number of paid placements per page. See examples.

The end result is a marketing channel that is extremely targeted - your advertisement is only displayed to prospects who are actively searching for your product or service. Many times, to the prospect, paid placements seem no different than a ‘natural’ search result, dramatically increasing the effectiveness of the advertisement. Furthermore, you are only charged when a prospect reads your advertisement, and clicks-through to your website.