Lately I have been working with a couple of website analytics and event tracking services, Google Analytics is normally my goto service for this type of thing but it has a lot of limitations especially when you want to delve into the behaviours of specific users.
I had a project where I wanted to track the behaviour of registered users, specifically the types of content the users were interested in and what features they were engaging with. My first thought was to build an event tracking system into the site which would log activity along with the users member id, this way I could easily pull out stats related to each user. This approach would have worked but I don't like to reinvent the wheel so I went looking for a pre built solution.
The are a number of event tracking and analytics products but I settled on Mixpanel, primarily because of its price. I wasn't sure if this system was going to generate any useful data so I wanted something that wouldn't cost while I got it up and running.
Mixpanel revolves around event tracking, its very similar to Google Analytics event tracking but provides some more advanced reporting tools and crucially the ability to uniquely identify users between sessions and domains. The data can also be extracted using the api and fed back into internal account stats.
They have also recently added people tracking, so along with the events you can set some additional metadata for each user, name, registration date, email, this is used to provide a fantastic interface to view member signups and activity, one less system to build.
Over the new couple of months I will find out if I made the right decision.