In a recent analytics tool review, my impression of Mixpanel is that it aggregates and reports on data but has no on-site data collection capability which I feel is a huge setback to the platform.
Data collection would include on-site events using dimensions and metrics that encompass the entirety of user behavior on the site. Further, the capability to implement data capture without coding expertise (such as a mapping system or tag manager) would allow companies without a lot of technical resources get an analytics platform completely off the ground.