Patreon is like an ongoing Kickstarter, often without a physical product.
In other words, you’re buying content by supporting the creator of that content.
For example, I support the Daily Tech News Show which is my favourite podcast.I support it because it is run by an excellent journo, it’s five days a week, they know Australia exists, and it’s the main source of my tech news, so it’s reasonable to contribute a small amount to their funding. I get value, I give value (to steal their saying). This allows them to run without ads, which is great.
I pay monthly, other models allow you to agree to pay when the creator releases a piece of content.
The principle is that if enough give a little, then professional level enterprises can be funded. DTNS has about 4500 patrons, others have a lot more, some have almost none. They currently have about US$15K/month pledged, less Patreon’s cut.
A lot of places give extras if you’re a patron – DTNS gives you a different podcast feed that includes pre- and post-show content, which I very much enjoy having done radio for so long, but it’s really interesting stuff anyway.
Strange fact you may already know if you like weird indi bands – Pomplamoose dude Jack Conti is a co-founder.
(I’d have put a link to the mission statement/about page if they had one, but they either don’t have anything useful, or it’s too well hidden if they do.)