Re-Marketing is a strategic advertising scheme that prompts the user with advertisements of items/products/services that they recently searched for on the internet. e.g. A potential customer or lead who recently used (say) Amazon app or visited their website to search for shoes will see ads of the shoes from amazon on a platform like Facebook or Instagram, etc.

Re-Marketing proves to be a highly cost-effective way of marketing because the chances of conversion are extremely high since the customer is already interested in the product and because you now know what kind of product the customer is looking for and can lure him by sharing appropriate ad.