I like that they offer many different services, including the ability to send bulk emails or use their API. They do not have any built in analytics so it's difficult to see how your campaigns are performing. Also, there is no way to add an auto responder directly from the platform so you must go through support and ask them to set up an autoresponder. They also charge quite a bit for each campaign sent. Make sure you really understand what you're getting yourself into before signing up with this service. We used them to send out a weekly newsletter as well as promotional emails about new products we were launching.