[jmarshall]

Correct, though clearly from a business perspective it's silly to try and sell the application, as anyone that you sell it to can then distribute to anyone else at no cost.

Thus many companies either sell a service or hardware, rather than attempting to sell the opensource software itself. That way their customers can distribute the software to their hearts content - the company still makes money as they supply something of value over and above the software itself.

Cheers,
Jonathan