I’m a statistics junkie. Picking some significant metrics, and sticking with them to measure performance is the only way to figure out what’s working and what isn’t. I usually try to design in some measurement tools, but that’s hard with Facebook apps, since their setup hides the referring address/previous page and other useful information.
Luckily, they recently introduced a new statistics page for every app, which you can access from the More Stats link below the application name, from the main developer page.
The first big innovation is the ability to see how many people added and removed you during the previous 24 hours. Before, you could only guess at this by comparing the user totals from day to day, but this wouldn’t tell you how much turnover you had from people removing your app. The most useful part of this, and one that’s a bit hidden, is that the total number of adds is actually a link. If you click on it, you’ll see a bar graph like the one above, showing you exactly where your new users came from.
The top picture is for Funhouse Photo, and it tells me a lot. I was suspicious that my app was very non-viral because the growth in users was very linear, but this confirms that I’m getting the majority from the directory and direct searches, rather than feed stories or other friend-to-friend communications. To improve growth that needs to change, and I’ll be able to tell very quickly if alterations to the app help by looking at those stats.
Less exciting, but still very useful, are the response metrics. I’ve had a recurrent problem with time-outs on my facebook apps because they’re doing heavy processing on the server. It seems like any page request that takes more than 8 seconds to complete results in a Facebook error screen for the user, so to work around that I had to implement asynchronous Ajax loading of page elements that might take a while. Looking at the response statistics shows that both my apps that use this aren’t returning error pages for any users, something I couldn’t verify before.
The final interesting feature is a selection of the URLs that were requested from the app recently. This sampling is a great way to figure out how people are using your app, which features they’re accessing and how often. My apps generally encode a lot of information in the URL using GET rather than POST, so I’m able to get quite a fine-grained look at my users’ interactions with them.
Funhouse Photo User Count: 1,723 total, 95 active. As I mention above, I’ve got new insight into the growth pattern from the add statistics. It explains why growth is so linear, there’s little friend-to-friend spreading of the app.
Event Connector User Count: 71 total, 11 active. The add source statistics show that most of the trickle of new users came from the product directory, which is what I’d expect since I don’t have a conference signed up yet.