Doc Searls, August 2012:
"In May of this year, ClarityRay reported that the overall rate of ad blocking by users was 9.26% in the U.S. and Europe. The rate ranged from 6.11% for business and finance sites to 15.58% for news sites and 17.79% for tech sites. For some sites, ad blocking reached 50%. Ad blocking is highest in Europe, where Austria is tops with a 22.5% ad blocking rate. The U.S. is slightly below average at 8.72%. With 1% or less are Iran, Guyana, Kuwait, Myanmar and Qatar.
Ad blockers are also the most popular software extensions for leading browsers such as Chrome and Firefox, which at 17.81% has the top ad blocking rate. Microsoft's Internet Explorer was lowest, at 3.86%
Coincidentally, also in May, Microsoft announced that the "Do Not Track" (DNT) feature will be turned on by default in the next version of Internet Explorer. (Many browsers already have it, but it's off by default.) In addition to being a browser setting, "Do Not Track" is an initiative proposed by the Obama administration, similar to "Do Not Call" for unsolicited phone calls. The purpose is to encourage businesses to respect the wishes of users not to be tracked. Microsoft's move angered the digital marketing industry, which would prefer to see DNT left as an opt-in for users rather than an opt-out. But Microsoft knows which way the wind is blowing, and it's blowing in favor of customers." (http://online.wsj.com/article/SB10000872396390444873204577535352521092154.html)