well if you are selling out all the time of one section you must do one of two things... buy more seats or raise your price..
What I have seen from really successful team is that they will literally have a 30k capacity stadium and have their prices real cheap. so instead of 10k bleacher seats selling out at 8$ a pop.. they will sell out a 20k worth of bleacher seats at 5$ a pop... (That is a VERY basic example.. im not confident on the exacts) But that tend to be what I have seen.. it takes a TON of arena investment. just scope out successful arenas of guys in div 2... Obviously you gradually get to that point... the more patient you are, the quicker you get there. Its really a crappy exercise in will though.. to sit there and basically not play the game.
Another thing you could do is literally sell all of your players and go Geriatric a few years. Sell your young, well paid players in exchange for wily vets. This more than likely wont promote but it is a decent way to avoid demotion instead of complete tanking... You can also, with a little luck, make it a ways in the tourney If you do this.. get the trainer that specializes in career extension.. They can make a big difference in the rate of decline.. and vets have something the younger guys don't.. experience.. which people think controls things like shot selection and so forth..
I truthfully, don't have a lot of patience... so I tend to wallow in div 4 and 3. I need to bite the bullet soon and go all out for my arena.