An email marketing list is just what it sounds like—a list of email addresses that you use for an email marketing campaign. As a marketer or sales professional, you know umpteen places you can get these lists. You’ve also likely spent money on poor-performing lists that didn’t bring in any sales. You want email addresses that are verified, deliverable and for people who are likely to be interested in what you’re offering. It’s far better to have a smaller number of quality email addresses than 60 cajillion emails that bounce or are marked as spam because they’re sent to people who don’t want to hear from you.