Was a lot of it classic word of mouth, email, etc.?
I imagine something like that, but I’m wondering as I feel like there may be some useful pieces of knowledge that may be worth recalling as people gradually start to move back out of the more centralized sites/services.
Yahoo was massive. It was the first attempt to organize the web. There was no algorithm per se, but there were endlessly nested categories that sites would self-select. It wasn’t really worth it then to game the system (or at least if people did I never heard of it). You wanted to be categorized correctly so that you could be found.
Yahoo was never as dominant as Google would become. There were alternatives like webcrawler, Lycos, altavista, etc. But they mostly just used a sort of brute force search; any website that contained your keyword(s) would show up and the site that contained the most keywords would show first.