Google AdSense is a way webmasters can earn extra money by adding advertising to their site. AdSense is free to use—all you have to do is sign up for an account. There are currently upwards of two million websites that make use of AdSense.
Google AdSense is very simple to use. First, you simply create a space on your website for the ad. It can be over to the side, in the actual content itself, at the top of the page, or anywhere else you want it to appear. The size of the space typically doesn’t matter that much—AdSense ads can be horizontal, vertical, or even square. All you need to do is copy and paste the AdSense code that Google generates specifically for your website into this space on your site.
While you’re doing this, advertisers are actually bidding on your space. This takes place in an actual real-time auction. The more an advertiser is willing to pay to appear on your site, the better chance they have of their ad showing up. Ads are selected by matching up the keywords advertisers have selected for their ad with the keywords assigned to your website. If your website keywords are flowers and florists, there’s a good chance you’ll have ads for various florists appear on the site. These ads are referred to as contextual ads.
There are also site-targeted ads. For these AdSense ads, the advertiser actually gets to decide which pages their ads appear on. Instead of bidding, they pay what’s called a cost per mile—the price for every 1,000 displays of their ad.
While Google started out with AdSense aimed at content, they later expanded. AdSense for video is a great way of adding advertisements to videos you’ve uploaded to YouTube and other video sites.
In the past, there were a few other types of AdSense, but Google has since rolled them all into their standard AdSense program. This includes AdSense for mobile (aimed specifically for those who use mobile sites) and AdSense for domains, a type of ad that could be placed on domains that haven’t been developed into actual websites. AdSense for feeds was also discontinued.
AdSense can be abused—there are some webmasters out there who try to create sites with very little content but with many ads so the user ends up clicking on one of them. However, while these were affective in the beginning, Google has since began shutting down their AdSense accounts.
