Implementation details aside, this is a fantastic use of metrics in two ways: it exposes them to the user in a way calculated to improve their experience, and it provides hard data that this feature is printing money hats. It also establishes a baseline for further improvement (I would be tempted to pull a Zynga and show the user a progress bar at 95% saying that they are almost done and the one little thing they can do to complete their listing is to make with the clickyclicky.)