Coventry also promote well within some schools, a stand at the Motorcycle Live at the NEC, taking bikes and riders to various places like ToysRus! Trouble is, it doesn't seem to make that much difference to getting new support some maybe the promoters decided they had no choice. It is very easy to pontificate when it isn't your money that is at stake.
What I would like to see is Promoters/Management/riders having meetings with existing supporters to see how new supporters can be brought in. Current supporters are more likely to get some success with this approach.