[tboughen]

I think there is a distinction between a charitable donation pop-up that forces the user to round up, donate, or actively select 'no donation' is a dark pattern.

Whereas having the option to select a charitable donation, or passively ignore it, as a part of the normal checking out is fine.

[csomar]

Yeah, if these donations where accessible via a different menu (ie: you have cafes, cake, juices, donations) then I'd be fine with it. I'd go to the donation individually if I want to.

The problem is when you put the donation at checkout to "improve" conversion.