Although ATi has gained a lot of success of late, you have to realize there's still a fairly large amount of proprietary machines(Dell, Compaq/HP, etc...) purchased not long ago when those companies thrived on Intel's intergrated graphics solutions, found in a lot of small business' and consumer households.
primary MBP Core i5 2010 | HR | OCZ 120GB SSD
gaming Core i5-2500K @ 4.1GHz w/ CM Hyper212+ | MSI N560GTX-Ti TF II/OC | MSI P67A-GD55 | Silverstone FT02 | X360 250GB + Kinect
htpc IONITX-A-U | 2GB | M350 | XBMC Linux | SABnzbd, sickbeard, couchpotato | NAS Synology DS411J | 4TB
hometheater KURO PDP-5020 | Marantz SR6005 | Definitive BP7001s, CLR3000, BPVXPs