Each of the 450 or so fan-funding platforms tweak their rules to cater to different groups of creatives or to emphasize different results. Crowdfunding sites can optimize for musicians (PledgeMusic, SellaBand), nonprofits (Fundly, FundRazr), medical emergencies (GoFundMe, Rally), and even science (Petridish, Experiment). A few sites (Patreon, Subbable) are engineered to supply continuous support to an ongoing project like a magazine or video channel. A couple platforms (Flattr, Unglue) use fans to fund work that has already been released.
