[dethstar]

>If people are asking/begging for the tool to be open sourced, then they do indeed value it. Otherwise, why would they care if it just withered and died?

If we are talking about a start up, what about current clients? Maybe your business could not be sustained by the number of clients you had, they do find value in but they can not by themselves sustain your business.

[aragot]

Yes it's totally allowed to sell a product under GPL, for example to give it only to the real customers who paid for it. Those are then free to share, but since they know how much it cost them, they may choose not to.