Email Marketing is great. By adding a sign up form to your website you can begin to gather people’s emails. The tricky part is getting people to sign up. You might try offering a coupon if your working with a E-commerce store. If your working with any other site you might try offering something a little different. Use some creativity if you have to. When you have peoples emails you can create re-targeting campaign or let people know when you have new products or projects coming out. It might take a little work to set up and run but it is worth it in the end. That is of course if you want more money in the bank.