Some of them charge
success fees just like
investment bankers, typically in a range of 4 - 8 % (FlushFunders, GateImpact, OneVest, CircleUp, MicroVentures, etc.) or flat monthly fees
as an informational («service») portal where no securities transactions are executed (such
as EquityNet, CrowdFunder, etc.) or a combination of both (SeedInvest).