We don't know that it is profit-generating, since the author doesn't take a salary. As for the assumption that the profit would be soaked up by the market salary for the founder, the fact that he's a former Google engineer or whatever is a pretty decent indication that this is true.

I would agree that most people would take some job flexibility/autonomy in lieu of part of their bigco salary, but my guess is that this particular Xoogler would be making well more than $236k (including stock) if he had stayed at Google.

EDIT: that doesn't mean he should have stayed at Google, just that his market salary would very likely soak up all of the profits this year. If he can keep up the growth (and ramp down his hours), then it would be clearer that the enterprise could throw of cash even after paying for all the labor.