Obligatory Topic.
On an internet forum or board, used to segue back to the topic at hand after the discussion has diverted off on a tangent.
Post 1: X is expensive.
Post 2: I didn't get an X, I got a Y instead, really cheap.
Post 3: My Y broke really quickly.
Post 4: I imported my Y from Iceland.
Post 5: Did you know they don't have a Z in Iceland?
Post 6: No, I didn't. ObTopic: If you're looking for an X for cheap, try the post office.