Oldschool email marketing services like MailChimp or Aweber (and lots of other services too) use Contact Lists to store your subscribers separately. But over time and as the complexity of your marketing grows you will face a serious issue: you will have to deal with tons of lists and lots of wasted information! If you would like to implement a modern marketing automation solution that relies on behavior-based activities to send highly personalized emails, you should use Contact Tags and Segments only and leave the concept of email lists behind! This short guide shows you why and how to do that.