When deciding to participate in pay per click advertising there are factors to consider such as keywords you will have to buy to be assured coming up on the first page of search results and how much those words will cost. Depending on the popularity of the keyword, they can be pricey and too expensive for many websites. However, for the bigger sites with deep pockets it can mean generating a lot of traffic.
When pay per click advertising was first used, companies could manipulate the results by creating their own multiple clicks on a specific ad. Search engine companies spotted this practice and quickly made adjustments to make the recording of multiple clicks from the same computer in a certain time frame meaningless.
Additionally, with many network pay per click programs, if the owner of the website clicks on a pay per click ad it could result in termination from the program and the loss of any income previously generated. Even if the site owner is interested in an ad, it is in their best interest to find it another way as opposed to the risk of losing the program.