I play in a couple of dynasty leagues, am commissioner for one of them. The one I commission is with a group of friends / colleagues which helps with people sticking around for multiple years, which is key to a successful league. We have a nice perpetual trophy where winner's name is engraved each year and gets to keep the trophy, so we play for that and pride. No money - it is tough to do money in dynasty because teams could be bad for multiple years, it is fun to rebuild but people will quit if they have to pay in each year knowing they will lose. Depth of the league is important, I think 16 teams to 20 teams (20 is max on Yahoo) is a good number, deeper rosters if 16 teams. It makes draft picks for valuable, for rebuilding and trading picks. We do 2 round rookie / FA draft each year, slow draft via chat, so people can take their time, make trades. We had 11 trades go down during the draft this year, over the course of 3 days and it was a ton of fun, people trading up to take another manager's target pick, trash talking, etc. My suggestion for league depth is to think about how many rounds rookie draft you want to have, say 16 teams, 2 rounds, then to make the rookies who are in reality drafted in latter part of first round or early second round useful, you'd need to be about 240 deep so roster size of 15 or more.