YouTube blog informs that currently "the amount of video uploaded to YouTube is 35 hours per minute" -- in Mar it was more than 24 hours every minute.
"That breaks out to 2,100 hours uploaded every 60 minutes, or 50,400 hours uploaded to YouTube every day. If we were to measure that in movie terms (assuming the average Hollywood film is around 120 minutes long), 35 hours a minute is the equivalent of over 176,000 full-length Hollywood releases every week. Another way to think about it is: if three of the major US networks were broadcasting 24 hours a day, 7 days a week, 365 days a year for the last 60 years, they still wouldn't have broadcast as much content as is uploaded to YouTube every 30 days," explains YouTube.
As you can see from the above chart, the number of uploads to YouTube have more than doubled in the last two years. Here're contributing factors: