The ability to send mass emails with the click of a button. There's also a great analytics tool available through the software which makes it simple to see who opened your emails, clicked links, and more. There aren't many features that I don't like about Campaigner. It works well as a tool for large scale campaigns, but can be a bit confusing if you're just getting started. We use Campaigner to collect contact information from our customers when they book their services. This allows us to follow up with them regularly and offer special deals or promotions.