You need people to email, so you can tell them about all the great products you have. But what is the best way to do this? Do you buy a list? There are many reasons why you shouldn't buy a list. The main reason is good addresses aren't for sale. These same lists are sold over and over so that makes them pretty worthless if you expect to get a response from them. If you had a list of good email addresses you would use it and not sell it. When a list is sold the value goes down and you don't know if the people will be interested in your product.
The best thing is to have an opt-in list. People come to you and sign up for information. This means they are interested in what you have. People need a reason to sign up like offering free eBooks, webinars, templates, etc. Make sure people can find it on your site. A popup opt-in work the best, but also have opt-ins throughout your site. Now that you have your list, you can run a good email campaign.