I would also cut the automated emailing portion after a few days, and actually write an email after a few days explaining everything rather than having it automated. Tailor that email to their business type by noting specific things about Bitcoin and their specific business.
That's what I suggested with the "volunteers can step in"-part. Just in case there is no volunteer for that specific business, I would keep nagging them until they say what should happen with the money sent their way.
Hmm ... I don't think my such website would qualify to reclaim that bounty.