You probably already know of Google Adsense if you have been a webmaster for a while or even if you spend a decent amount of time on the internet. Adsense is basically a must have for most websites, and I would have to say it is the most commonly used program out there today. Here is a short description of the program if you already don’t know about it:

Google Adsense is an ad serving program run by Google. Website owners can enroll in this program to enable text, image and, more recently, video advertisements on their sites. These ads are administered by Google and generate revenue on either a t per-click or per-thousand-impressions basis. Google is also currently beta-testing a cost-per-action based service.

Google utilizes its search technology to serve ads based on website content, the user’s geographical location, and other factors. Those wanting to advertise with Google’s targeted ad system may sign up through AdWords. AdSense has become a popular method of placing advertising on a website because the ads are less intrusive than most banners, and the content of the ads is often relevant to the website.

Popularity: 47%