All clubs could do with extra fans coming through the gates but I think the problems are much greater than not enough fans, the increased cost of everything including insurance, medical cover, shale etc plus riders wages .
The overall structure of the League could also help matters with riders DU up or sometimes in three Leagues at times.
Which clubs are doing well enough to stand without major help....Poole, Ipswich ? but even these clubs rely on plenty of Sponsors I believe but this is the case now in all sports.
Scunthorpe for example get by with having Stock car meetings to off set the Speedway ( i'm sure someone will correct me if I'm wrong) , so stadiums need to be used for other events like the Greyhounds used to be.