Pam, we are sure JetPack has nice features and all but it allows you to add a blog / comment subscription module only. On the other hand services like MailChimp and Aweber are professional email service providers offering many powerful features which allow you to really benefit from the email list you are building. As far as simplicity is concerned, we are slightly more inclined towards MailChimp, they have a great user interface even for absolute beginners, they have excellent documentation, and lots of resources to learn how to use each feature available.
Just what I needed to learn how to promote my own products! The products, sales letter, auto responder sequences, available help, are all super important for a newbie like myself. Hey, I can even use the products for my own education. The graphics are unbelievable. This program is worth its weight in gold. Everything is clearly explained! - Joseph Daniels
However, if you are willing to invest some money in your learning, I would heartily recommend that you stop reading immediately and grab yourself a copy of Start a Blog that Matters. This is an online course developed by the aforementioned Corbett Barr, and I cannot recommend it enough. I have been running through the course material over the last couple of months, and it has revolutionized my approach to blogging (which some of you may well have observed with interest).
Email marketing has the highest conversion rates of any marketing channel. In fact, sixty-six percent of online consumers made a purchase after receiving an email marketing message — which is more than social and direct mail, according to the Data & Marketing Association. And transactions from email are three times more profitable than those made on social media, reports the global management consulting firm McKinsey & Company.