Charles Perry:

Proponents of this model call it “patronage,” but it has little in common with the historical concept of patronage where a well-off patron paid an artist an amount to commission a work of art. This new model, in fact, is the opposite of patronage. Instead of requiring a patron to provide money up front in exchange for an item of value, this new model gives away all the value in advance and requires nothing from those who receive it. It less resembles patronage, or even commerce, than it does begging, or busking if you’re feeling generous.

Interesting point of view, although I personally have a different take on the subject—set a high enough price to make your useful product sustainable and market the hell out of it. There is a tiny flaw with my theory: most people don’t want to pay for software, even when it’s really well done.