Sure, but this is not selling GPL software. This is giving GPL software out for free, and selling proprietary software. I'd be interested in cases where people

Sure, but this is not selling GPL software. This is giving GPL software out for free, and selling proprietary software. I'd be interested in cases where people have made substantial money selling GPL software as if it were proprietary software; that is, where they are able to get the consumer to pay for the software after a short trial, in order to retain the privilege of using the software long-term. The GPL grants this privilege anyway, which is the problem. The consumer doesn't gain any value by exchanging their valuable money for something they already have (the right to use your software), so they don't do it.