I like that it allows me to target my messages towards specific audiences, which is very important when marketing through social media platforms such as Facebook & Twitter. It also gives us an insight into who we're reaching out too - so if there's someone within our team/company whom no one has reached yet then this helps identify them quickly! Nothing at all really- good product by a great organisation. If nothing else just use their free trial first before committing yourself fully. We have been able to reach new customers quicker than expected because of its ability to build targeted lists from scratch.