That is correct, there was no way to have multiple hosts on the same machine. One of the start-ups I helped build (engineer #2) in early 1997 (which still exist

That is correct, there was no way to have multiple hosts on the same machine. One of the start-ups I helped build (engineer #2) in early 1997 (which still exists today in some form that many young, single men have spent quality time alone with) had a landing page, so that if your browser did not provide the host header, it would give you an index page of all the salacious sub websites/sub-domains available that you could then click on - it was an image map, naturally. We were very careful to keep the heterosexual and the homosexual offerings on physically separated servers so that customers did not complain about "accidentally" clicking on content that they didn't want to see. Latest versions of Netscape at the time supported the host header, but Internet Explorer very explicitly did not. And IE was the default for many people just getting online for the first time outside of AOL/Compuserve.