Important Afternoon, Jan 17 -- Facebook has just informed us that the new dau_rank metric is not entirely correct and this is leading to holes in the data. You may noticed shuffling of dau ranks over the next few days. Given that we don't know the severity of the issues or where the problem starts to affect things, we're keeping the dau_rank metric but please use it with caution.
In January of 2013, Facebook has introduced a new approach to metrics: ranks. Facebook has simplified MAU and DAU reporting by categorizing each app into a MAU/DAU tier, supplemented with a ranking that indicates how well an application is performing against all other Facebook apps.
Example. Let's consider a widely-used application like Zynga's FarmVille 2. All MAU/DAU metrics for this app are now reported in rounded tiers such as 10 million unique users, 5 million unique users, 1 million unique users, etc. Since FarmVille 2 has a large user base, it will be reported in the 10 million MAU tier and the 1 million DAU tier. To see how FarmVille2 is performing compared to other apps in the 10 million MAU tier / 1 million DAU tier, you can look at its MAU Rank and DAU Rank, which indicate where the app lies in the spectrum of MAU/DAU values. A low value indicates a more successful application; a high value indicates a less successful application.
Gaps in Rank. You may notice gaps in MAU or DAU Ranks that AppData reports. Due to limitations on the data we get from Facebook, we're not able to track every single application; for example, some apps are tied to specific geographies that we aren't able to index at present. This is an issue that we are working to address.
WAU. Facebook does not currently offer WAU Tiers or Ranks as it does for MAU and DAU.
Historical Data. All historical data will retain the same level of granularity as before the Facebook reporting change. This means that any data before January 2013 will not follow the new tier/rank reporting model, but will remain in AppData as previously reported MAU/DAU/WAU metrics.
MAU/DAU Tiers. The tiers for MAU and DAU metrics are as follows:
|Rank Type||Data Tiers|