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.
A free software license is a software license which grants recipients extensive rights to modify and redistribute, which would otherwise be prohibited by copyright law. To qualify as a free software license, the license must grant the rights described in The Free Software Definition or one of the similar definitions based on this.