This is a good update of an old principle/device. The resulting product is simple but effective.
Warning, though: The ad says "The Coin Ditcher is made using readily available, low-cost materials." But this is only true if you own an angle grinder. Otherwise you'll have to take some of the readily available low-cost materials to someone to do the work for you.
This is not mentioned anywhere in the advertisingI consider this a significant omission.