The number of seasons a league has run means nothing really since some leagues sim at a much faster pace than others. 20 or 30 seasons is impressive until you see that a league sims a 12 weeks of a season each real week.
The USBA is now in its 12th season. We sim 1 week at a time, 3 times per week. We began in March 2002.
Here's the impressive part – from the 20 teams in that inaugural season we still have 15 of the people involved as team owners in the league. 3 of our 4 expansion owners (which came aboard in our third season) are still running their original teams. The success of the USBA is derived from the solid ownership base that has kept the league consistent and thriving.
Many people here don't even know about the USBA because we have never advertised for owners here. We do no recruiting and really don't keep a formal waiting list. If someone wants to join the USBA they usually send an email and I keep their info handy in case we do have an opening. We add people that seem to be a good fit with what we already have on board.