The staunch fanboys/girls will always buy the new jersey, irrespective of how crap it looks, but the more NRL club boards allow their teams' jerseys to resemble NASCAR's, that number will shrink.
In European football, clubs have one major jersey sponsor, integrated most of the time, but they don't struggle for cash, and the companies sponsoring them still get plenty of bang for their back.
The NRL should step in and introduce the following rules re. jersey sponsorship:
1 major sponsor on front of jersey.
1 minor sponsor on neck of jersey
Manufacturers' logo on sleeve, no bigger than 5cm high and 10cm wide
1 sleeve sponsor
1 lower back sponsor
Upper back reserved for players' last name.
In turn, revenue would increase as fans would be more inclined to buy a jersey with their favorite players' name and number on the back, especially in a code like ours where players stick around at one club for much longer.