I'm not saying that no one will take infringing copies without paying, just that the marginal number is less than the marginal benefit of the additional publicity. What I can't figure out is why you didn't take the opportunity to sell a video to the guy who called you! There's something between just rolling over, and wishing you could go through the phone and choke him! I would have reminded him that you depend on your sales, and offer to sell him a clearer copy.
But I'll lay odds that what you did, helping him, might well lead him to buy from you in future.