Patreon allows patrons to give money for supported content. Patrons decide how much they will pay for a particular kind of update, and when a creator tells Patreon such content has been posted (or posts through Patreon), only then are patrons charged. Patrons can decide to withdrawal their support at any time (before supported content is posted) with no charge. Like Kickstarter, Patreon encourages dividing patrons into "levels" who get corresponding rewards and provides reporting tools for keeping track of who is owed what.
So this all sounds great, right? What an innovative service, huh? Well, it turns out that for about four years, PayPal has offered a feature called Adaptive Payments (AP). This API can be used to implement the Patreon model, as well as many others. With AP, one PayPal account (the patron in the Patreon model) gives another (the creator in the Patreon model) permission to make charges in the future. With AP, a site creator need only take in a pledge amount and then get AP permission from the patron. Using Patreon, a creator "pulls the trigger" on charges by informing Patreon of the supported content being delivered. With AP, this process is more direct, and the creator simply charges the patron the pledged amount when the content is ready. Like Patreon, PayPal offers a variety of reporting tools to manage rewards and so on.
That PayPal has long offered such features should be obvious when one strips away the Kickstarter-like trappings of Patreon and looks at what it actually does: allow a vendor to make charges at some point *after* initial customer approval. When a PayPal vendor sells shoes but only charges the customer once they've physically shipped, it is completely equivalent to a Patreon interaction. A customer has "pledged" money contingent on shoes shipping, was only charged when those shoes shipped, and could have withdrawn their support/committment at any time prior to the shoes shipping.
While there are some wrinkles that make Patreon look different, from a security perspective AP and Patreon are practically the same. Patreon being limited to charges in a set amount doesn't stop a creator from falsely telling the service that they have delivered supported content as often as they like just as nothing stops an AP vendor from making false charges. Patreon has spending limits, but so does PayPal. In both the case of PayPal and Patreon, refunds and disputes are settled by a party who is not the creator. Basically, both systems require roughly the same amount of trust in the content creator.
On the point of trust: PayPal is a publicly traded company that is over 16 years old and processes over $145 billion dollars in payments a year. Patreon is a private VC company and has not disclosed its payment processing volume, which is understandable as it has only been processing payments for a little over four months. The trust/popularity argument doesn't hold water. For example, Patreon only has a few hundred more Twitter followers than Love Me Nice itself! XD
About the only thing Patreon seems to really offer are some social features (fundraising thermometers, etc.) and to provide these features creators must ask patrons to sign-up for yet another social service. DX
Here's a chart with a few other aspects of comparison:
Created with Compare Ninja
Guess beard combs aren't cheap. XD