Best of all is to have a value proposition for them that benefits their core business. You eventually want all the promoters in the country driving users to you, now is a good time to figure out your value proposition to them.
Second best is to pay them for usage that they drive (think of them as a lead gen partner and pay them accordingly, maybe CPA).
Worst is equity. The reward will seem too remote to drive incentives, and they may even start to feel like co-owners with their own ideas about strategy.