I heard you say on a couple recent Halo Wars 2 skirmish tournament videos that there isn't enough people signing up and I have an idea/pitch for you. Usually tournaments are top 1 or 2 take home money, but what if you spread out the pot more and made it more 'grand prix' style with the top 5 or even the top 10 all win some money? For example:
1 - $25
2 - $20
3 - $15
4 - $10
5 - $5
Personally, I think it's unlikely that I could win the tournament so signing up for just a top prize doesn't make a ton of sense. But even if it's not about the money, getting a prize for making top 5 in a tournament of 15 or so would be a cool goal to shoot for.
Lastly, if you take this idea to heart and want to try it out for a big 2v2 skirmish tournament where the prizes are much more substantial please let me know. I'd be interested in supporting financially so we could generate enough interest.