Gamer: I'm going to buy this $10 game I want, and I'm donating $10 for malaria eradication.

Friend: If you actually cared, you'd skip the game and donate all $20.
Friend: What's more important? Games, or mosquito nets and medicine for kids?

Later:
Gamer: I think I'm going to buy these two $10 games I want.
Other Friend: Cool; which ones?

{{Title text: I usually respond to someone else doing something good by figuring out a reason that they're not really as good as they seem. But I've been realizing lately that there's an easier way to handle these situations, and it involves zero internet arguments.}}