Estimate the number of YouTube users.

There are two types of youtube users: 1. Content Creators 2. Content Consumers. Since content consumers is a larger segment we'll estimate the number of content consumers on Youtube. Is that okay?

I: Yes

Assumptions

1. We are looking at all unique users across youtube web and mobile

2. We are looking at all free and paid youtube users

3. We are trying to identify the daily active users for Youtube

The overall population of the world is 7.5B. Out of this countries like China and north korea don't support/allow youtube. To take that into account remove ~=1.5B.  

Overall users with access to youtube are 6 billion.

~=50% world population has access to the internet. So, the number of users with access to the internet are ~=3B.

Youtube is a major source of news, entertainment and learning for all the users around the world. I would say ~70% of the active internet users are on Youtube. 3B * 0.7 = 2.1B

We can categorize all the youtube users into 3 different categories

Passive users: use Youtube once a month or less ~= 50% of all the users. Generally people under the age of 15 or over the age of 50 or students preparing for competitive exams or jobs etc.

Active users: uses youtube twice a week, mostly weekends  ~=40% of all the users, majorly working professions 

Power users: use Youtube to watch live streams, games, news, learn, listen to music or just relax every day. ~=10% of total users.

DAU = 2.1B * 0.1 + 2.1B * 0.4 * 2/7 + 2.1B*0.5*1/30

~= 0.21B + 0.24B 

~= 450 million

The DAU for youtube is roughly around 450 million.