aWeber is an autoreponder which can automate follow ups when someone joins your list.
Do not confuse this with an email newsletter. They are nothing alike. eMail Newsletters are dead in most industries as people have finally figured out that most people do not want their news.
On the other hand, people do want to get a series of emails that help them with a problem they are having.
I wrote the aWeber review because I am passionate about that product and very appreciative of how much money it has helped me make.