[Gasp0de]

I don't think META is looking for investors. And for advertisers, only the wasted time of those who are shown ads is of interest.

[octacat]

Stock holders, fixed :) It is a pretty good metric of how the company is doing. I.e. if paying customers still spend a lot of time on the app, they would pay the next time. If the time decreases, there is a risk they would not prolong subscription.