Specifically, the company purchasing a PPC campaign pays the advertising publisher every time an advertisement, such as a text link orbanner, receives a click.
The result should be on-the-fly brand research that enables you to re-craft your messaging mid-campaign as well as giving you a tool to focus the keyword lexicon, orbanner and display spend.
In the year to come, security professionals are warning of bank code-stealing exploits that are much slicker and more convincing--hidden in guises as harmless as abanner ad on a reputable Web site ora message from a friend on a social network.
That either means Outbrain and Taboola have killer sales people (which they probably do), or they can prove that linking people to good content will make them more money than a standard ad banner.