Earlier quoted context omitted.
I'm not entirely sure that's correct. If you try to sell something that relies on GPL software, it's considered a derivative work even if you don't distribute the GPL software with yours.
It is a derivative work, but selling derivatives of GPL-ed software is entirely legal and not forbidden by the GPL. Distributing binaries (regardless if for free or not) of GPL-derived software without distributing the source from which the binaries were derived (or without offering a reasonable way of getting the source on demand) is forbidden by the GPL. Moreover, the source of the derivative work must be offered u…
Absolutely you can sell, but your can't restrict user rights