You’re absolutely right. But how many of those services charge 10% of revenue? Zero.

And if 10% of revenue uncapped isn’t too much “because not interested”, why not 20% or 50%?

You’re obviously welcome to pay 10%, I just think it’s foolish once revenue hits a certain point.

Edit: think of it this way: you already have $20k per month of paid newsletter revenue and you need a new membership billing provider. Other options are $20 - 100 per month and won’t go up any more. Would you even consider one with the same or fewer features that’s $2000 per month (and will take 10% of every marginal dollar from there)? I really doubt it. I love sleek, simple, elegant tools, but I won’t pay any price for them.