The ability to send and receive emails, the ease of use, customer service, the ability to track and manage your leads and the ability to send out a weekly newsletter. I haven't found anything I dislike about this product. I use it on a daily basis and have never run into any problems with it. I have been able to track my leads and manage them from anywhere in the world. I use it to send out newsletters to my clients and prospects on a weekly basis. The ability to send a weekly newsletter is a great feature.