I found you could also choose more different formats. OK, there was no video (thank God), but you could have unobtrusive text links, you could have banners, little buttons, HTML blocks, and so on. And yes, also annoying pop-ups and flash ads...
You also had paid content, which is absolutely taboo and vilified today, but I believe it was not nearly as bad as we think. It was certainly better than some alternatives (horrible pop-up-ads that installed dialers, does anybody remember them?) Back then, I was proud to not serve evil or annoying ads, and to promote articles from partners on my site - including setting links to them to promote their page ranks. (That Google shows links among search results that they get money for, but forbids slightly improving the position of search results when other people got money for it tells a lot IMHO.)
One alternative to the current situation would be for sites to serve their own ads (from their own servers). I wonder why this isn't done at least from big sites?