i just finished reading harry, a history by melissa anelli the webmistress of the leaky cauldron. it's about the history of harry potter (how the idea come about & how the books got published) and craziness that followed, which didn't explode until 1999 when the third book was published and livejournal started. in many parts of the book you could remove the words harry potter and insert the name of most any fandom (star trek, star wars, stargate), since the book touches on many issues fandom deals with; fanfic, canon, shipping wars & spoilers. while reading it i started thinking; what would fandom be like without the internet?
the first thought i had on the subject was that fanfic would not be as....prolific, i guess is the right word. people would still be writing it, but would probaly only share it with a few like-minded friends or in some fanzines. discussions would be limited to phone calls and get-togethers at conventions or an occasional meet-up in person. (would e-mail exist in a non-internet world? if i recall there was some versions before the internet, but that was mostly limited to universities so probably not.)
there would probably still be watching parties where you get a group of friends over to watch the show as it aired. i recall this being big with xena & x-files. (does anyone still do that?)
you would only have to worry about spoilers if you recorded the show, didn't get a chance to watch it & everyone is talking about it at work/school the next day. or there was some write-up about it in the news paper.
role-playing games would be a lot different, probably just limited to friends getting together to do that sort of thing on weekends or something.
i suppose there's other things that would be different but i can't think of them.