"Can you think of even one GPL product that has been successful through sales of GPL licenses? "

Actually yes, I can think of a quite a few. Redhat is a good example of a huge industry built around GPL software.

That really isn't the point though, and allow me to summarize your misconception.

"nobody else needs to purchase it because the first customer can simply give it away to everyone for free and you have no recourse."

Explain to me how this applies to GPL and not the BSD, (I doubt you can) and you will see how (at least this particular) argument is flawed.

You are not required to give that first customer the source code with BSD.

The only companies that make money on software containing GPL'd code are doing it server-side with pre-GPLV3 or AGPL'd code. I've worked at a lot of companies that used and created open source software; and the rules are invariably the same: No GPL'd software allowed into the source tree, period.

<blockquote>You are not required to give that first customer the source code with BSD.</blockquote>

That's only different if you are selling other people's software. If so, why should anybody have any simpaty?

It's also true if you are selling original software that borrows one line of code from somebody else's software.

You could conceivably try to claim fair use, in that case, although it would undoubtedly be easier (and easy enough) to replace that one line with something original.

Red Hat don't sell software, they sell support contracts.

That is patently not true: This Agreement establishes a framework that will enable Red Hat to provide Software and Services to Client. “Software” means Red Hat Enterprise Linux, JBoss Enterprise Middleware and other software programs branded by Red Hat, its Affiliates and/or third parties including all modifications, additions or further enhancements delivered by Red Hat.

You are absolutely correct, although the point still stands in the context of the discussion. They aren't making money from accepting money in exchange for GPL software (people can just grab CentOS if that's all they want), they're making money from support, services, and non-GPL software that gets bundled along with a bunch of GPL software.

The discussion is about whether someone could run a business that is every bit as financially successful as a business that sells proprietary software, by asking for money for GPL software, and not having any other sources of income. Some posters seem to think this is feasible; I would disagree.

Quantum Leaps does dual licencing for the QP framework and commercially licences exactly the same code that it offers under the GPL. http://www.state-machine.com/licensing/index.php#Pricing

It is a common method to monetize software development by the use of exclusion, and threaten ones customer with lawsuits if they don't comply.

Is such abuse the most effective way to reach financially success? Maybe. Does it matter?