Twitter Says iOS 8 Bug Cost It 4M Users

Twitter said Thursday that its lower-than-expected number of monthly active users (MAUs) was caused by a "bug" in Apple's iOS 8.

Announcing fourth-quarter earnings, the company attempted to explain why its current level of 288 million monthly active users fell short of an expected 292 million. Mashable transcribed the relevant comments by Twitter CEO Dick Costolo and CFO Anthony Noto during a call with investors and analysts:

Anthony Noto (CFO): Let me just give you some specific numbers as it relates to iOS. So we said we lost 4 million monthly active users due to the iOS 8 integration. One million of those monthly active users were Twitter owned and operated monthly active users.

And 3 million were on Safari, what we call auto-pulling MAUs, and we lost those. We don't expect to get the three million auto-pulling MAUs in Safari back, and that's a non-Twitter owned and operated auto-pulling MAU. The one million, that number was actually higher at a different point in the quarter and we were able to bring it back to just one.

Dick Costolo (CEO): Let me add a little bit more color there that may be helpful. We obviously have a great relationship with Apple ...

On the second part of what Anthony talked about there, there was an unforeseen bug in the release of iOS 8 as it relates to the specific Twitter integration into iOS. That's why it was particular to us.

Once we understood the issue, we moved as quickly as we could on multiple fronts to minimize its impact. But it wasn't a one-size-fits-all fix, which is why you've seen some of the complexity that we've seen here in bringing those users back. The problem was complex and affected different users differently.

The good news for Twitter is that its fourth-quarter revenue of $479 million exceeded analyst projections of $453.34 million.