Instead of relying on a group of editors or solely on the frequency with which certain terms appear, Google ranks every web page using a breakthrough technique called PageRank™. PageRank evaluates all of the sites linking to a web page and assigns them a value, based in part on the sites linking to them. By analyzing the full structure of the web, Google is able to determine which sites have been “voted” the best sources of information by those
Junk traffic can also suck the life out of your campaign. Most, but not all pay per click services or providers distribute a segment of their budget to several search engines and other sites via their search partners and content networks. While you certainly want your ads displayed on Google and/or Bing, you may not want your ads showing up and generating clicks from some of the deeper, darker corners of the Internet. The resulting traffic may look fine in high-level statistics reports, but you have to separate out partner network campaigns and carefully manage them if you’re going to get your money’s worth.
The flat-rate model is particularly common to comparison shopping engines, which typically publish rate cards. However, these rates are sometimes minimal, and advertisers can pay more for greater visibility. These sites are usually neatly compartmentalized into product or service categories, allowing a high degree of targeting by advertisers. In many cases, the entire core content of these sites is paid ads.