Facebook's $2.3 billion deal for Oculus VR left the 9,522 backers of the startup's online fundraising campaign with T-shirts and trial products.
Oculus initially raised cash on Kickstarter, a service that rewards donors with test versions of its wares and other token compensation.
Newer crowdfunding sites are giving investors the chance to earn something else: money. CircleUp Network offers equity in private companies, while Funding Circle lets investors buy company debt. College graduates can turn to Social Finance to refinance loans with help from alumni.