DAU = Daily Active Users – typically defined as non spam users who’ve logged into the service on that day.
Twitter’s mDAU for Q4 2018 is: 126MM DAU
Twitter defines monetizable daily active usage or users (mDAU) as Twitter users who logged in or were otherwise authenticated and accessed Twitter on any given day through twitter.com or Twitter applications that are able to show ads.Twitter investor comms (pdf)
So, why the additional filter of “monetizable?” Most reporters allude to an attempt to obfuscate comparisons to Snapchat – that claims to have 186MM DAU.
I believe Twitter is not doing its comms job properly. If they believe this is the new meaningful metric to track and trust and orient the company, it’s good to align the internal and external folks to align on it. Any obfuscation doesn’t do it justice. Its definition doesn’t do justice given its continued war on third party twitter apps.
That said, I personally think it’s an interesting move to shift to DAU as their primary metric. It’s twitter accepting their role in the current attention landscape – likely interesting and likely the place for people to go to get a sense of what’s happening right now. However, the caution here is that pre Cheeto in Command, there were niches – politics twitter, tech twitter, sports twitter. Twitter is relying on something interesting to happen every single day. Now, this has the same caution as the 24 hour news channels — what happens when things are normal? Is there an incentive to treat normal things are ‘newsworthy?’ I’d urge twitter to consider the 2nd and 3rd order effects given what facebook is going through right now.