Patreon is a site content creators can join to earn more money. I think it is donation based, where artists produce work, and people can donate if the so choose to support the creator.
Some content creators will offer certain things in return for patrons donating to them, such as some artist saying if a certain number of people donate (say 5$) that they'll upload a reference guide or tutorial. Or they might even offer to exchange personalized art for someone's donation to them.