Re-marketing is a way of marketing that you "must do". In order to closing sales with people who have visited to the web, Re-marketing is a powerful tool that will increase your sales. The way of work is when someone who will be your customer, have visited your site. The system will keep a list of people who visited the site. If customers does not buy your product in the first visit, when he left and go to visit other web sites, your product Banners image will be appeared, to show him more so he remembers that he is interested in this product. 

To stimulate consumer demand. To make people remember the brand and come back to buy your product again, just like Agoda, Lazada  use this method and they have been succeed and achieve a lot.