Ease to use & understand. We had used Google analytics before but never understood what we were looking at until now because Panviva does exactly that - explains all our website's stats in an easy-to-understand way. Nothing! Their support services are incredible and they also have a great community forum. It would be nice if we could see some more detailed reports regarding their data sources though. We can't seem to access them either through an API or via their site. It's great for tracking traffic and user sessions through out web pages, etc. I like how easy to use this system was for our organization, we were able to set up an account in less than 10 minutes! The fact they have so many options makes learning about them very simple as well (we are still trying some new things). This program can be used by any business or non-profit organizations at no cost which made us feel better knowing someone else would benefit from using their services if needed down the road. We haven't found anything yet; everything has been great thus far!!