Sometimes when it was new ad and a new product, just to test it. Most of the time, it stayed at that one test, because it couldn't beat the product I was using until then. But sometimes, it did, and then of course I bought the new one instead of the old one. However, I don't think that this happened more than 6-7 times in almost 20 years now.
The Nintendo eShop rating Thread: http://gamrconnect.vgchartz.com/thread.php?id=237454