I like that they are constantly improving their platform, which makes it easier for me as an agency owner/marketer who works with them daily! They have been able reach out when we've had issues or needed support from time-to-time (which is great!). The only thing about this service in general - not really anything specific but just generally all services offered by MailChimp etc., would be if there were more resources dedicated towards helping you understand how your campaigns work at scale so YOU can do what's best vs relying solely upon MC insights team knowledge base articles / tutorials + API docs alone? We're solving big problems here @MC & our customers love us because results matter most!! The ability for us to create, edit and send out emails in minutes instead of days is great! I like that we can easily track our open rates and click throughs. It's not as easy to use as other services but it does offer some customization options. We are able to have more control over creating campaigns than with MailChimp or Aweber. Our customers love being able to see their order status right from an email they receive about their purchase.