Using this for marketing purposes for one of my clients, I how you can set up numerous categories for genres and that contacts in the system can be placed in one or more of such categories. Good reporting features on response activities in the email portion. And key is that it serves the purpose of not having such communications of large scale reporting as spam to servers and thus avoiding getting red-flagged, just for sheer quantity of messages sent out.
It does not play well with LinkedIn Business Pages for sharing such posts/messages. I still have to go in and individually post on my Clients LinkedIn Business Page and it has to be from another source as the Constant Contact formatting does not look right. A recent update for shares to Facebook has also proved to not be a positive step. Also, any time my client wants to make a change to our personally created template, which can not be saved as a Template, I have to perform a lot of recreating the wheel. Another issue is that their system will sometimes have hiccups and place some contacts in an "undeliverable" state, and if it is there for a time, it becomes a 'blocked' contact and you are not able to send emails to that individual any more through no fault of yours or the person you are trying to message. Regarding their Sign-up tool, allowing people to sign up works decently enough, though it would be nice to have a filtering feature so that individuals can select only wanting emails when it is both/all X category AND Y category to better pinpoint their interest without making the sign-up list so massively long with so many detailed variations that it becomes overwhelming. And for anyone wanting to make changes to their current email preferences, it is not an easy thing to accomplish for the less than average tech savvy individual (which many of our clients fall.
The biggest problem solved is getting emails out to numerous individuals through a reputable application that allows clearance by the various server watchdogs guarding against spam.