Sponsorship challenges
The problem with race sponsorship is that most races don't attract spectators. The audience consists of the participants and non-participant runners. That's just not enough for big-paying sponsors.
A typical race fields 250 runners. It may mail 5,000 entry forms, distribute another 5,000 at running stores, health clubs, and events, and draw 5,000 unique visitors to its website. That's far too few people to appeal to most sponsors.
Right now, Toyota wants to erect a billboard at Wrigley Field,where the Chicago Cubs play home baseball games. The company is not trying to reach the 50 team members in the dugouts or even the 38,000 viewers in the stands. That would not be worth the expense.
It wants to reach the millions who will watch televised games.
(A sign would not benefit an unknown company. But Toyota is well-known and the sign will reinforce its ongoing advertising. It's a big opportunity).
Running events need to identify sponsors who want to reach a niche market - the runners, supporters, and communities that are related to the event. That may be a small market but one that can be very valuable to the right sponsor.
Determine what your entire market has to offer (not just the event participants) and pitch that to a potential sponsor.