[imchillyb]

"How's it different?" is an excellent metric.

Why pay you, a person with this as their resume, when I can pay someone with 10 other 'hits' on their resume and their software also does this?

Why pay the newb is a great question to ask.

The answer to 'How is it different' is a whiteboard interview problem. If the developer cannot immediately extol the virtues of their product, do you want to give them money? Are they confident in their skills? Were they just copying other's recipes?

You'll know the answer to that and many other questions the minute the developer has to think and answer this fundamental question.

You'll also know if they're full of shit almost immediately.

It doesn't matter what the developer's prior relationship to you was. When they hand you software, and expect others to pay for it they need to be asked this question. Their answer will assist them in understanding their product and how to sell it to others.