"5% market share" might be roughly true on a global scale in terms of unit sales, but it doesn't tell the whole story. For example, Mac OS X is used for about

"5% market share" might be roughly true on a global scale in terms of unit sales, but it doesn't tell the whole story. For example, Mac OS X is used for about 15% of desktop web traffic in the US: http://gs.statcounter.com/#os-US-monthly-201211-201301-bar http://gs.statcounter.com/#os-US-monthly-201211-201301-bar Among certain groups it is higher; for example among college students, software developers (especially web developers), graphic designers, and advertising agencies. So part of this is that the companies producing the web sites you're looking at are simply using images of the computers they happen to be using. Apple is a well-liked brand with a public image of luxury, polish, usability, etc. Companies probably want associate themselves with those qualities in their own marketing.