At Twitter, size matters.

There’s no metric more important to the social network than the number of people that use the service — more specifically, its monthly active users, or MAUs. Recent events inside the company show how sensitive Twitter’s top brass can be about this number, which also partly explains the company’s push to use other metrics to showcase Twitter’s reach.

The company used to grant all employees access to its MAU figure through an internal intranet, but that access was revoked a few weeks ago, according to multiple sources familiar with change. Now, the MAU metric is only available on a need-to-know basis.

In other words, it’s under lock and key, most likely to keep it from leaking outside the company, these sources say. As a public company, the numbers are too valuable to share with all Twitter employees. (It’s actually surprising it still shared these stats internally more than a year after hitting public markets.)

A Twitter spokesperson confirmed that employee access to this MAU figure and other important non-public info has been limited to only those who need it for their job.

There was also a story going around Twitter’s offices that it was looking to increase its MAU number by adding Vine-only users to that total — a move that could boost that number by millions. Vine is the video-sharing service Twitter bought in 2012. When some members of Vine’s engineering team heard the story, they felt this was shady and were so upset they threatened to quit, according to one source.

The company’s general counsel, Vijaya Gadde, alerted employees to the story on the company’s internal message board and said it was a rumor, according to a separate source. A Twitter spokesperson confirmed to Re/code that Vine-only users are not included in Twitter’s MAU total, adding that there was never any plan to include them.

One thing is certain: Twitter still cares about the size of its immediate user base. A lot.

We reported previously this number will be a focal point during Twitter’s fourth-quarter earnings call Thursday. Twitter has been criticized over the past year for slow growth, and while it started pointing toward other metrics to goose its size (aka its “logged out” audience), the industry standard remains the “monthly active user” figure.

It’s the number everyone will look at first later today, and Twitter stock will move based on how close it comes to Wall Street’s growth estimates.

Twitter has been very busy over the past month, launching both finished and test products intended to help do things like attract new users and encourage the existing ones to tweet more often.

News also broke Wednesday night that Twitter is partnering with Google to show tweets in Google search results. It’s a partnership that should help inflate this “logged out” audience as people come across tweets when searching for other things online.