The approach that Altavista took didn't scale with web growth. It was based on the idea of database searching, where the engine was supposed to return all pages that matched a query. This meant that you couldn't expect to type a generic term and get a useful result; you'd be overwhelmed with random pages. You could find pages that contained an exact phrase, and this could be useful for finding out what some error message means. But as the web exploded in size, the results you could easily get from Altavista got worse and worse; you could fight by adding more and more qualifiers to filter out what you didn't want, but junk results were mixed in with good results.

That's why Yahoo had a business: search engines were of limited use pre-Google, so you needed a hand-curated list to find the good stuff on the web.

Google was first to figure out an effective algorithm to rank results by quality. People immediately stepped in to try to game the system with link farms, junk tags and the like, but even so, it was a revolution.