Number of purchases to be entered manually?

Am exploring the distribution. While most features seem straightforward, the only part I don't understand is where it shows "n purchases!" right below the date countdown. From what I see, this info is to be entered manually in product editing page. Does that mean, every time when someone purchases the deal, the site admin should go in and update the number manually? That sounds like heck lot of admin work to do! Is this the normal practice? Is this how Groupon does it? Puzzled...