The ease of use, and the fact that it is so easy to set up! I have been using it for about 2 years now and I have never had any issues with it. It's really easy to get started with, and you can do all sorts of things like create different types of ads, change layouts and sizes, etc. You can also easily add in other tools like analytics, tracking codes, etc. There are some very helpful tutorials out there if you need help getting started. If you're looking for a tool that will help you manage your advertising campaigns, this is the one. We've been able to increase our sales by around 20% since we've been using it.