The report measured mobile web consumption based on mobile OS for smartphones in North America, and listed iOS (nee, iPhone OS) as the leader with 58.4% marketshare. Google's Android is in second place with 19.9% of the market and RIM is next with 10.4%. The remaining 10.9% is split among other mobile OS players like Nokia, Microsoft and Palm.
While it's no surprise that iOS is still the leader in this category, what is impressive is the rate at which Android is growing not only from month-to-month, but also year-over-year.
Check out this chart, which shows the change in market share both from April to May 2010 by month and quarter over the last year:
In every category, Android's market share has risen, whereas iOS's has decreased. Now, to be clear, the smartphone market as a whole has grown over the last year, so a decrease in market share is not he same as a decrease in number of devices -- the pie is just now bigger, meaning that each slice is smaller proportionally.
Still, the numbers are significant -- iOS's share of the market has decreased 8.1% whereas Android has increased 12.2% over the last year.
As more Android devices hit shelves it will be interesting to assess the impact on the U.S. market.