Is it like a kid screaming and paying people to shake down restaurants?  Not really.  The essence of the problem solved is information asymmetry.  To see this, break the app into two apps -- one that simply informs you that you missed out on a deal and makes you feel bad, and one that compensates you and makes you feel better by giving you a savings.<p>This is a side-payment, as in Coase&#x27;s theorem.  You are outraged at the side-payment, but that just hides the information asymmetry under a cloak of disgust.  There is no valid reason that the purchaser should <i>not</i> learn the price subsequently dropped -- but the nature of homo economicus being what it is no one will use the first app without the second.<p>This app is an application of Coase&#x27;s theorem, and takes an externality (uninformed consumers are like a clean river to dump bad pricing into at a profit) and internalizes that cost by making companies pay it -- it is always better for the market if costs are internalized, assuming markets work at all.<p>It doesn&#x27;t matter whether the company or the consumer pays, according to Coase&#x27;s theorem.  The result will be the same.  We might invent reasons to be outraged that the company pays, but really all that has happened is a market inefficiency -- information asymmetry -- has been eliminated. Prices are less sticky and more flexible. This is good.