Really... how do I have fun with Forum Roleplays? It boils down to three things:
1.) In addition to the already quoted 'Different Strokes for different folks', I could invert the question: How can one not have fun with Forum roleplays? I have come to Forum Roleplays from Chat and Messenger-based roleplays, but those, summing things up, had a lot of flaws. For once, I am bad at fascinating someone with a story seed at call. I have ideas sometimes, good ideas every now and then, but I can't just draw those from my pocket. With a forum, there is the option of putting these ideas on a list, and a partner can be found, if not now, then at some later time.
2.) The other issue is time. Particularly in a chat roleplay, it's either that while you're chatting, some other matter that is more pressing arises, or that you just can't reserve enough time to enjoy a play from the beginning to the end. With a Forum roleplay, I can answer when I have the time. I can store a reply and write it bit by bit when I have the time, I can edit and polish a post before I put it in a thread. When I'm not feeling creative, I can postpone a reply until I have something adequate.
3.) And last but not least: Forum roleplays tickle my fantasy just more. You're right - it may take hours, days or weeks even until you have a reply. But on the other hand, with all my partners, every post has been worth the wait. And in the meantime, you can re-read the story up to then, bask in the sexiness that it already had, and draw some inspiration from that. Also, a complex story just writes better on a Forum, with more explanatory parts in between the smutty sex.
4.) And last, but not least, there's one more thing that made me have fun with all my Forum Roleplays: It's the partners. All of those have become pretty good acquaintances of mine (I shy away from saying friends, because we haven't gotten daft-drunk together so far). And people whom I really have grown to like.
[Rule for authors: Announce three items, deliver four :)]