If the average American gets around 7 hours of sleep each night, that leaves them with about 17 “active” hours each day. According KPCB and Mary Meeker’s 2015 Internet Trends Study released this week, a third of that time is spent engaged with digital media. Even more compelling is the rate at which this time spent is growing.

Since 2010 the average American adult has added about 2.5 hours of time spent on digital media to their day, increasing, on average, about 30 minutes each year. That is a 75% increase in time spent online compared to five years ago.  The interesting thing to note is that desktop/laptop time spent has remained stagnant in this time period. It is the mobile device that has driven this growth.

In terms of the ad opportunity, given the steadiness of time spent on desktop/laptops over the last five years, ad spend has been able to catch up. On the other hand, mobile usage growth has been so rapid that the KPCB study puts the ad opportunity on mobile at around $25B in the US.

Compared to last year’s study, mobile time spent and mobile ad spend increased four percentage points.  The rest of the increases and decreases in time and ad spend were modest across all media except TV which saw a four point decrease in ad spend.

While it isn’t explicitly clear based on these charts, the growth of digital media may be having an impact on TV ad spend as advertisers diversify spend to account for more mobile and desktop opportunities. However, what the study did find is a growth in the consumption of video content via mobile.  According to the study, mobile video viewing accounts for 29% of video view time vs. just 5% in 2010 while view time on TV has roughly remained the same in that same time frame.

By eliminating the physical boundaries of accessing the online world which once existed in the desktop era, connected mobile devices have led to an overall increase in the consumer’s time spent on digital media. From an advertiser’s perspective, this only makes digital an even more powerful and necessary media to leverage.  And as we can see, video content appears to be a major influencer on this activity.