Easy setup for new users; easy integration into other platforms such as MailChimp or Constant Contact - very intuitive! The platform does not offer any native customization options (such as adding your own widgets) so you are limited what features can be used within an eDM campaign.
There's no built-in analytics like Marketo offers which makes it difficult at times when trying to find out how well each part of our campaigns was performing during different stages of user engagement. We use this service primarily for automated outreach via mass emailing but do utilize some customizations including sending welcome messages upon signup.