I don't think it's evidence for that at all. We aren't talking about sustaining a cashless society, but about establishing one. Amazon realizes that we aren't there yet, and probably aren't extremely close; until it does arrive, they don't want to leave that cash money for other retailers. This might slow the motion TOWARD a cashless society, because having such a dominant player accept only e-money probably did exert some pressure on those who would prefer not to deal with it. I do find it odd that the article mentioned Amazon's established pre-pay option ("give us your cash now, so you can buy stuff from us later"), without mentioning the ominpresent Amazon gift cards, available at every corner retailer. I'd buy one of those with cash if I wanted to leave no traces.