Remarketing lets you reach customers who have previously visited your site or shown an interest in your product.
Display remarketing takes you beyond Google Search, allowing you to target previous site visitors.
Using networks like Google or Facebook you are able to target users on the websites they use most, using dynamic and attractive rich images or text to give users reasons to convert.
Some ways you can use remarketing to build on your existing marketing are:
Convince customers who haven't yet purchased to come back to your website. Upsell or Cross-Sell previous customers with similar relevant products. Build your brand and encourage repeat visitors to remember your company in future.