You are a PM at YouTube. You released a new feature. It doesn't matter what feature was released. After the release, number of mobile video views went up by 10%, and number of desktop comments under videos went down by 20%. What would you do?

Clarifying Questions:

Did the mobile Video views go up and desktop comments went down for the same videos or we are saying total video views and total desktop comments under videos? Total

Are we assuming live videos also because live chat contains 1000’s of comments for single video? No

Are both independent problems?  NO

Was this happening for certain type of videos (Gaming, entertainment, News etc.)? No

Is the change specific to a certain geography? USA, India etc.? overall

Is this change observed with certain user segments? No

Is this a gradual change or a sudden shift? Gradual after the release of feature

Describe the product:

YouTube's mission statement is “to give everyone a voice and show them the world.”

Views are meaningful way to quickly interact with video.

Comments on Videos enable user to communicate their opinions and deeper reaction to video.

Internal Factors  

Did we change the approach we are tracking these metrics recently? 

Did we launch feature like short form videos that contribute to number of mobile video views went up and low engagement on desktop?

Did we do any PR Campaign to encourage watching videos on mobile?

External Factors

Are we observing same trend with our competitors? 

Was there any social issue recently that led to more video views on mobile?

Was there any product or feature launch from competitors?

Hypothesis:

Since this trend is observed only for YouTube, I will look at internal factors: #1 and #3 are easy to identify. Most like the change is due to the launch of short form videos.

1.       People like to spend time on YouTube by watching short- form videos on mobile. So, number of mobile video views went up.

2.       Short form videos have commenting feature inline leading to more comments on mobile. people prefer to watch long-form videos on desktop. thus, desktop comments are going down.  

Solution:

we should change the way the metrics is calculated for comment as mobile video view has gone up it means more comment would be coming on mobile. Desktop view might be going down due to which comments are going down on desktop.