[wp-hackers] General consensus of "Premium Theme" concept

[Otto]

There's two real cases to be concerned about when trying to sell GPL
code, in general:

1. Selling to the public.
2. Developing specific code for a client.

For case 1, this can get tricky, because any code you sell to the
public they can then give away to other people for free. However, this
is the standard piracy problem, with the side effect being that it's
legal for them to do it. There is no solution to this problem, except
to sell something else. Instead of making code once and selling it
over and over, sell support or customized code or something like that.
Nobody ever said that you could write the killer plugin and then
retire.

For case 2, this is not so much a problem as many people think. If you
develop a theme or a plugin for a client, then that client has the
ability to give away or resell the code, but there's nothing saying
that you have to release it for free. The GPL doesn't make things free
as in beer, it makes them free as in speech. And realistically, the
client doesn't have any particular reason to give away their code,
they paid for it, why should others give it up for free?

The standard answer to selling GPL'd stuff is to sell services instead
of source. Sell custom development, create a web service that does
something people want to use, sell support. Writing something once and
selling it over and over is not a good business plan in the long run,
because you only "own" that code by virtue of laws saying that you do
(copyright law). And those laws can change from place to place and
over time. Copyright won't be around forever. Basing a business model
on intellectual property is not a decent long term strategy.

-Otto