PPC or Pay per Click is the most popular online advertising model. The main reason is that its pretty efficient, but the marketers love it also because its pretty simple. Basically, PPC is an advertising structure in which the advertiser pays for each ad click made via the website of the publisher. How much they pay depends on the deal between the advertiser and the publisher. PPC is the model used in Google AdWords campaigns. The average cost per click in this program is between 1 and 2 dollars, although it all depends on the keyword, that is, its search volume and competition. The most expensive keywords can reach the price of over 50 dollars per click!