I like that they offer all the tools needed for a successful campaign without requiring any additional products or services from our side. They also have an excellent customer support team who are always ready to help us out whenever we need it. Sometimes it takes some time to get used to their interface but once your familiar with how things work here, everything becomes very easy! There isn't anything specifically bad about using them, other than perhaps that sometimes certain features could be improved (e.g., adding more templates). We use Mailbluster to manage our newsletter campaigns as well as many of our social media accounts.