Mixpanel , an analytics-focused startup whose backers include Y Combinator, Michael Birch , and Max Levchin , has hit a big milestone: it's now processing over 1 billion actions per month. To put that in perspective, a year ago the company had recorded 80 million actions cumulatively . Mixpanel was built by former Slide employees, who took their experience with that company's extensive analytics tracking and built tools that other developers can integrate into their own applications. These datapoints can include pretty much anything a developer wants to track, from the number of pages a user has viewed to how many virtual cows they've thrown in a Facebook app. Cofounder Suhail Doshi says that the volume of data the site tracks grew 185% last month alone (you can see the growth chart below).