I started working on a very similar concept a couple of years ago, I called it PatronPie(.com). Patrons could specify a set monthly amount they wish to spend, t

I started working on a very similar concept a couple of years ago, I called it PatronPie(.com). Patrons could specify a set monthly amount they wish to spend, then divvy up the "pie" by assigning percentage-based slices to their selected recipients. Participating recipients could have an "Add us to your PatronPie" button on their sites that would give them a small, adjustable default slice. Patrons could edit their slices and monthly amount at any time. Monetization was easy, I just transparently took a percentage of each month's transactions by having a set slice of pie permanently pre-allocated to PatronPie. I suspended the project when I discovered how hostile credit card companies are about letting an entity move funds in this way. Obviously it's possible to get special permission, as there are companies that do it, but I lacked the time and resources to push through the hassle barrier.