If you want to increase customer loyalty to the brand - hold a sale. But how to understand which products will be of interest to buyers at a discount? It's simple - ask customers which product to offer them at a promotional price. Do it right in the mailing text: ask clients to go directly from the letter to the online store page, where the voting script will be placed. Let customers see the voting process and the result that the majority will choose. As soon as the voting is completed, send another letter, but with a proposal to buy the product at a profitable price. Or you can make an even more tricky combination - arrange the voting in the mailing list by setting up the service so that the data about those who voted for each product are collected by the system into one group. When the voting is completed, you will have several groups of subscribers to whom you can send letters with a unique offer. You'll see, the users will ask themselves to arrange similar sales with a personalized offer in the future. And client’s preferred products range will give your marketers ideas about future special offers in e-mails.