I think he was asking a different question.
That depends on where your starting point and ending point are. You want the pockets to be roughly the same distance from the midpoint seam as from the side seam. You can cheat that in at the midpoint seam, but go too far and it starts looking dumb. A guy like me, you've got some margin for error, and can take in roughly 2-3 inches. The slimmer you are, the less margin for error you have. If you're less than a 30 waist, I'd say two things: a) these aren't for you; and 2) find yourself a ham sandwich and a Vermonster.
If his profit is measured in orders of magnitude (as I suspect it is), why would he care? Quick sale high margin is every entrepreneur's dream.
Oh, opps, I misunderstood the question. I was told, to be on a safe side, no more than 2 to 3 inches.