(For those who want to read about it, dA has an article here: [link]
It sounds interesting, though it seems there are comments about 20% being too much.
I personally can't get past the pricing (in general for commissions not the widget only). How do artists gauge their prices D: ? I'm always stuck on that part. Maybe once I do figure out a good pricing system, I'll use this widget. (I do like that the widget isn't just for premium users though!)