Agreed with all of the above. I can add a little more about community games that are not succession forts though. That is, one that you control entirely.
Keep in mind that I have not read your previous fort (I don't read any these days), so none of this is a criticism of anything you might have done. Just a suggestion.
Gimmicks definitely pay off here, but I also strongly encourage you to take time to make your fort updates worth reading. That is, try to work a little narrative into important things that happened, include screen shots, and so on. Those were the things that sucked me into Boatmurdered before I started playing DF, and which have kept me interested in any that I was part of. Nothing turns me off from reading a community fort than finding one with zero images and only a single sentence for every date mentioned in the update journal.
Boatmurdered would have been way less interesting if it went like this:
"1st Granite
We killed a lot of elephants but there are still a lot outside."
instead of like this:
"1st Granite
I can hear the elephants at night. During the day, we look out from the walls and can see them. They're standing there, staring back, with beady little eyes full of hatred and the lust for dwarven blood. Right now, I hear them again. The trumpeting chills my soul! The trumpeting!"
Or however it went. Too lazy to go look it up and find the post I'm thinking of specifically.
That's all outside of your control if it's a succession game. You can still try to hook people with a good first post / update, but once you hand it off to others you're at their mercy. You can see this in Boatmurderd too, for that matter. Many will not have the investment to put in that much effort, and this is a big reason that I haven't been part of any succession games.
Worth repeating that a good community game is a lot of work. Making updates worth reading like I said above takes time. I probably spent 30-60 minutes typing up each update I posted in my own forts, even when there were few or no players at the time. It helps to write them as you're playing though. If something interesting happens, pause, take a picture and write up the paragraph or whatever in your fort update right away. If you wait until it's time to post, it's way harder to get the motivation to type it all up.