piatkow - 7:33 am on Apr 26, 2010 (gmt 0)
I know a lot of non techie users just can't be bothered to download a new browser. They feel that IE works for them and "downloading" is a dangerous thing that lets viruses into your computer (not realising that most malware is probably targeted at IE users). These are the ones that are most likely to click on ads.
If G gets a deal for a major reseller to pre-install Chrome as default then the figures will probably change.