The ability to create custom emails for each of my clients, as well as being able to send out mass emails with links in them! I like that you can customize your own templates so it's easy to make changes when needed. It takes time getting used to but once learned its very user friendly. There are some glitches here and there which cause delays or errors at times (which isn't always their fault). If this doesn't work then try another service provider because they have been great about providing support if we run into issues. We use Vidreach primarily for our newsletters/emails sent several times per week.