I know a guy who is great at winning hackathons. He doesn't make a living off it, but has definitely made at least 100k in the past few years (divided across his team, however). I entered my first hackathon last year, and it was one he was attending.

It was really disappointing. Maybe it was just that specific hackathon? I knew "the pitch" was a big part of winning, but didn't expect it to be 99%. A few teams built some actual cool and functioning things in 24 hours. Ours was the only app with a real demo you could visit/download, rather than it only working locally on the dev's machine. But the only teams that reached the finals were the ones with great speakers and a good idea, even if it wasn't functional at all.

The guy I know ended up winning the first prize at that event. His team had an amazing idea and a great pitch, but their "app" was a powerpoint presentation, and a couple static HTML pages that faked a dynamic user flow. It worked as long as you clicked the correct image map area, and entered values into text boxes that matched what was hard-coded into the next page.

I had fun with my team and made new friends, but it was really discouraging to lose a "hackathon" mostly because the other team had better speakers and not for technical reasons. I guess I prefer game jams, no qualms about marketability or a pitch with empty promises. Maybe it's because game jams usually don't have financial prizes aside for the exposure?