When I think of Pay Per Click, I think of a marketing strategy that has two different sides - one where you pay for published ads and one where you get paid for publishing ads. Somebody is always paying for the click, whether it is you clicking on someone's ad or another person clicking on your ad. Pay Per Click depends on how you look at who is paying.

If you use Google to search the internet then you may find that your search results include "Sponsored Links" (on the right hand side of the search results page). If you click on any of the Sponsored links, the advertiser that placed the ad you clicked must pay Google for that click. If the advertiser is you, you are the one that pays. The price that you would pay depends on how much you have bid on the keywords used to generate the ad. This marketing tactic is called Google Adwords.

In addition to the ads being displayed with the search results, Google allows owners of websites and Blogs to display the same ads as contextual ads. Contextual refers to content that relates to the subject of your web page. This system is called Google Adsense. Each time a visitor clicks on an ad Google pays the owner of the website for that click. If you have traffic going to your web site and you display the Google Adsense Ads on a page and someone clicks an ad, you make money.

Note that Google Adwords and Google Adsense compliment each other and are in fact, the inverse of each other.

Google Adwords Pay Per Click is a good way to get quick targeted traffic to your website. Because you are paying for an ad promoting your site or affiliate link, those that click your ad will be directed to your site. The efficiency of your ad (click through rate or CTR) will depend on the ad copy and the keywords. The keywords that you have in the ads that are searched for dictate when your ad is displayed.

Google Adsense is a good way to make an "automatic" recurring income. Automatic assuming your ads are getting the clicks and generating the income you expect. Some tweaking of the ad placement, colors, etc. may be neccessary for optimization. When a Google Adsense ad on your site is clicked, both you and Google make a split percentage of the total of the bid price for the keyword that the ad was displayed and clicked for.

Another type of ad that is gaining in popularity is the Chitika eMiniMall. Chitika eMiniMalls are advertisements that display a picture and a description of the product, the best deals where the product can be purchased and a search feature. If you want to display Google Adsense ads and Chitika ads on the same web page, Google requires specific modifications to the Chitika ads.

Both Yahoo and Microsoft are in beta right now with their own equivalent to Google Adsense. The Yahoo ad network is called Yahoo Publisher Network (YPN) and Microsoft's network is called Adcenter. I have not tried these networks out yet, but I may find myself doing that if I find that ad clicks yield a higher amount or percentage to the web site publisher.

There are several other pay per click networks available to try as well. Some of these would be RevenuePilot, Bidclix, CBclicks, Adsclick and Bidvertiser. I am sure there are even more than this. If you are interested, search them out and see if they fit for your own website's use.