A duck walks into a feed store and asks, “Got any duck feed?” The
clerk tells him, “No, we don’t have a market for it, so we don’t
carry it.” The duck says, “Okay,” and leaves.
The next day, the duck walks in to the feed store and asks, “Got
any duck feed?” Again the clerk says no and the duck leaves.
Next day, the duck walks in, and asks, “Got any duck feed?” The
clerk says, “I’ve told you twice, we don’t have duck feed, we’ve
never had duck feed and we never will have duck feed. If you ask
me again, I’ll nail your feet to the floor.” he duck leaves.
The next day, the duck walks in and asks, “Got any nails?”
“No.”
“Got any duck feed?”