In progress NPD predicting tool

[Bofferbrauer2]

Megiddo said:

That they rank so high is indicative of just how much more they sold overall in that short period.

Let's go with a hypothetical to illustrate the point. Let's say that Gamestop has 4,000 units of the PS4 special console for its online stores. Let's say that after one day's time Gamestop has completely sold out of these units and the PS4 is ranked #1. Let's say that during this one day, in 10th place is the Xbox One X which sold 800 units. The next day, the sold out special PS4 is now rank #2 and the X1X is still rank #10 and sold another 800 units. So in terms of points, since the PS4 is sold out it only has the maximum points for one day, let's say 200. Whereas in 2 days X1X has two times the 10th place point total, let's say 180 * 2 or 360 points. So despite the PS4 selling more than twice as many units in the 2 day period, it has only a little over half of the points the X1X was able to accrue in that time. This leads to great inaccuracies and is why the requested change was so illogical.

If it's ranking still 5 days afterwards that just goes to show how much it sold in a rolling period compared to the competition.

I see where you're coming from. But these shops don't work that way, hence why points don't increase in a linear fashion and instead the closer you get to the top the more points a single spot difference is worth.

It's much more probably that masses of customers try to buy one by hoping to have someone choosing not to buy/card not being accepted, etc... and getting that console instead. These buying attempts keep them charting and nothing else.

Besides, from yesterday to today the consoles would have dropped a grand total of 3 spots on Gamestop. That just doesn't work with your theory and calculation as some items dropped more despite still selling.