Google AdWords is Google's main advertising product and main source of revenue. Google's total advertising revenues were USD$28 billion in 2010. AdWords offers pay-per-click, i.e, cost-per-click (CPC) advertising, cost-per-thousand-impressions or cost-per-mile (CPM) advertising, and site-targeted advertising for text, banner, and rich-media ads. The AdWords program includes local, national, and international distribution. Google's text advertisements are short, consisting of one headline consisting of 25 characters and two additional text lines consisting of 35 characters each. Image ads can be one of several different Interactive Advertising Bureau (IAB) standard sizes.
An open source license is a copyright license for computer software that allows the source code to be freely, that is by anyone for any purpose, used, modified and shared. This allows end users to review and modify the source code for their own customization, curiosity or troubleshooting needs.