Remarketing ads almost always perform better because you are showing ads to users who have interacted with you before! Think of it this way. Is it easier to sell to a warm audience or a totally cold one? Most users do not take action on their first visit to your website, they may do it after 3 or 4 visits. It is important to have remarketing tag installed properly on your website so that you can continue targeting these users after they left your website to bring them back to purchase.
For e-commerce stores, we make use of dynamic remarketing to ensure users get served the most relevant product ads – base on what is in their product carts or what products they last saw on your site.