One way to improve how much revenue your store can bring in is to reach out to customers who have already bought something from you. It takes far less energy to get people who have already bought from you to buy a product than it takes to get a new person who hasn't ever heard about you to do the same. Don't forget about your older customers. You should be regularly reaching out to them and letting them know about new products and deals on existing products.

One of the best ways to maintain communication with your existing customers is to let them opt in to your newsletter. You might already have a newsletter signup somewhere on your site, but you might as well offer it to anyone who is going to checkout. Doing so during the checkout process is relatively painless since you're already collecting all of their information. You only need to add a checkbox to the checkout to let the user opt in. The programming will do the rest.