I like how it pulls in data from LinkedIn, Twitter etc to create profiles of people who are connected with your target audience so you can reach out directly via email or phone call when required - this saves time! It's not easy at first but once used will be very useful indeed as we have been able use our CRM system less often now which has saved us hours each week by being more efficient!! We haven't found anything yet really dislike about using them however if there was one thing i could change then would say maybe make sure they offer an option where users don’t need their own domain/email address (we've had issues getting emails through).