Earlier quoted context omitted.
> I'd donate to charities on my own. But lots of people won't think to do so, and it can raise awareness too. And in terms of payment processing fees it is probably much more efficient to include a small amount extra in a larger preexisting transaction and pool it up across customers than if everyone were to go out and donate $0.50 or whatever on their own.
The problem is the store charaties are always awful. I donate to local charities that actually do good work with it (Non-affiliated-beyond-being-donor plug: https://www.nuci.org/ ), not to bloated “awareness” charaties like Komen.
And "awareness" is a big part of some cultures [0] as it allows for the distribution of the idea of caring without devoting some of one's life to the cause.
[0] https://stuffwhitepeoplelike.com/2008/01/23/18-awareness/