I don't think that it really helped get more players who are part of the game jam but there was a spike of almost double people viewing the page after I put up the trailer, it helped with downloads as well from what I can see on the analytics page.
I make trailers for all the games that I make so it's just something that I do, it only took me a few hours (not sure how many maybe 1.5-3) to edit so I think it was worth it.
Thanks for the info! We didn't make a trailer but did make animated gifs. Seems like making a trailer may attract more attention from the broader itch audience. Plus, I see jams as practicing for the real thing - making a commercial game someday. And trailers are definitely required to do that. So, I'll definitely be taking the time in future jams to throw together trailer. True, if you're doing a commerical game, hiring a professional to do the trailer makes sense, but I want to understand the process so I know what to ask, etc. Plus, you never know, maybe I'll turn out to be good enough at it myself.
