I think developers will sell access to the client or go to an ad-supported model. Those are the only real options. Either that or offer subpar software that only gets updated when you have a bit of free time. I would much rather pay for a software tool than be forced to see ads or put up with buggy software until the dev has the time and inclination to fix problems. Value-for-value. If you want something that brings you benefits, you have to be willing to pony up. Either that or you become the product (ads).