That's the conclusion drawn from comScore's annual look at the mobile scene in 2011.
The firm claims a total of 40 million tablets have shipped to mobile users across North America, the EU5 countries and Japan during the last two years.
Such a figure means the tablet market is growing at more than three times the pace of smartphones, which took seven years to amass such a userbase.
Symbian unsettled
ComScore also concludes that 15 percent of mobile consumers in the US now own a tablet equal to around one in seven Americans.
When it comes to the smartphones, it says 2011 was the year Android and iOS cemented their leadership position in the industry.
Combined, the two platforms boast almost 80 percent market share in the US.
In the EU5, Android in particular has been a strong performer, unseating previous market leader Symbian in the three biggest markets in the region Germany, France and the UK.
As a result, Android's total market share in the region has hit 31.2 percent, with iOS coming in third on 20.7 percent.
Smart consumers
"2011 proved to be a groundbreaking year for the mobile industry, with smartphones hitting the mainstream, tablets emerging as a formidable fourth screen, and consumers increasingly integrating mobile behaviours into their lifestyles," said senior VP of mobile Mark Donovan.
"As mobile channels present a more personal, social, and ubiquitous experience to consumers, advertisers and publishers have an opportunity to better engage target audiences, given an understanding of how to connect and leverage the unique characteristics of these emerging platforms."
In all, comScore concludes 42 percent of mobile subscribers in the US own a smartphone, with adoption even higher in the EU5, where smartphone penetration sits at 44 percent.
The firm's report 2012: Mobile Future in Focus can be downloaded for free from comScore's website.
