It's not too hard, unless they decide to also branch into things like loans and financial investment, plenty of companies take ACH payments and also pay out via ACH (besides just wages to their own employees). Really the main issue is ACH is limited to the United States and territories' banks last I checked, that's the only advantage credit cards have, since they are mostly international. So hypotheticaly under that scenario international users wanting to use Patreon would be shit of luck since there is no unified global regulation body for banks (yet) as NACHA has no jurisdiction in other countries (yet). Not really that big a deal, most of Patreon's 8% cut from everyone is mostly from Americans anyway. There's also other irrelevant-to-most limitations like transactions limited to $1M per day and similar. Though I suppose for the rest of the world they could simply use old school wire transfer, though that would only make sense for those that pay annually or something instead of monthly since fees for those are ~100x what ACH costs. Of course that's where crypto pegged to the US $ shines. Coinbase fees are usually like 2-4% last I used them, comparable to credit card transaction fees, with Backed.by taking an additional 1% cut (assuming Patreon didn't also switch to crypto).