There’s a LOT of merit to what Tim talks about. The goodwill type of sponsorship. Historically they have been the most common ones for sure. For the most part that’s where my sponsorship came from when I was actively racing.
The evolution of the web and social media has opened up new opportunities and avenues that did not exist before.
When I say build an audience, that doesn’t mean you have to become the crazy super serious baseball dad forcing your kid to be some kind of groomed performance puppet. Quite the opposite in fact. It’s something you and your child can learn about, have fun with and discover together.
Grow an audience/following with your adventures and stories. Be personable, human not a machine. The pressure level is entirely up to you.
In simple terms, you’re telling your story on the web. If nothing else, this adds value to any goodwill sponsorship you’ve acquired.
Wild Duck Racing is a great example of a father and son doing just that: http://wildduckracing.com/
Crowdsourcing, like what DarkhorsePros offer is another option to generate $. I’m bearish on that however, you’d really want a following of some sort beforehand for it to be a success.