Quattro is a pizza shop that delivers pizzas without any extra charge. It plans to refund the entire amount of the order in case the pizza is not delivered within a period of thirty minutes from the time when the order is placed. After two years it has stopped the policy of refunding any money in case of a delay of more than thirty minutes. The fact that it stopped the policy of refunds in case of a delay of more than thirty minutes is an example of a _____ strategy.