Google AdSense

Google AdSense is so far the best advertising media for both advertisers and publishers due to the many benefits it offers to all parties.

The Google AdSense advertising program was originally introduced on March 2003 by Google to bring advertisers, publishers and targets closer through the web platform.
It operates with the ad targeting and serving method, allowing advertisers and targets from all across the Globe to interact.

Due to Google's large influence on the web today, ads from advertisers are able to reach thousands and millions of people with the least stress. Of course, at the expense of some few bucks.
Publishers, mainly web developers also have the opportunity of making lots of cash from the AdSense program due to it's high C.P.C ( Cost Per Click ) by displaying ads from various advertisers on their contents (i.e. website contents, YouTube videos, Video Games).

Google continuously updates their ad sizes but still keep some sizes in their recommended lists. Using recommended ad sizes can noticeably boost your earnings since most advertisers bid on them.