A great way to stay in touch with the people who have visited your site and are interested in more such content is to ask them to sign up to receive future emails. This is commonly called a mailing list. A signup form can be a simple as the person's email address, or it may ask for their first and last names, and what area they're specifically interested in. For instance, one of our clients sold used printing presses and folders. His mailing list asked if the user was interested in presses or folders or both.
The actual signup form is but the tip of the iceberg. All the mechanics behind maintaining an email list is done by an Email Service Provider or ESP. There are a number of these companies each with different capabilities and pricing structures. The one I always recommend to my clients is MailChimp. Their capabilities are similar to other ESPs, but while the other ESPs offer a free trial of their product, MailChimp has a free-forever plan. If you have less than 2,000 subscribers and you send less than 12,000 emails per month, you can use their service for free forever. There are a couple of features that are present in their paid plans that are absent in the free plan, but these are minor. The main thing the ESP does for you is to make sure you don't run aground of the CAN-SPAM act. This law was developed to try and stem the tide of email spam. Your ESP wil provide guidance on how to build your list and what you say to them to help avoid your email ending up in people's spam folder.