There were several things going on. The ad below the search field helped. The agreements with various companies (e.g. Adobe) to stealth-install Chrome when th

There were several things going on. The ad below the search field helped. The agreements with various companies (e.g. Adobe) to stealth-install Chrome when their products were being installed helped. The fact that a lot of the hard work of getting web sites to be created to standards not just to "works in IE" had been done by Firefox helped. The ads on TV all over the place helped. The ads on posters in subways all over the place helped. Better technology and features are nice, but huge marketing spend and sleazy stealth-install agreements are nice too, if your goal is just market share.