I remember being introduced to Google search back in 1999, and found it such an improvement on Altavista that I switched immediately and never looked back. At the time Yahoo! was a purely human-powered categorised site listings tool, and Altavista was (as far as the results indicated) just based on keyword occurences. I remember in 1997 a University colleague being able to be top of Altavista for 'chat room' just by having that phrase repeated over and over at the top of his 'Beard and Moustache Chat Page'! (Don't ask.) Google instead used the Web's link structure to determine how relevant a page should be, and consequently all the keyword-stuffed pages disappeared.