Android (operating system) top-selling platform in April 2011, overtaking BlackBerry OS with a 31.2% smartphone share, according to "comScore". By the third quarter of 2011, Gartner estimated that more than half (52.5%) of the smartphone sales belonged to Android. By the third quarter of 2012 Android had a 75% share of the global smartphone market according to the research firm IDC. In July 2011, Google said that 550,000 Android devices were being activated every day, up from 400,000 per day in May, and more than 100 million devices had been activated<ref name="i/o 2011 stats"></ref> with 4.4% growth per week. In September 2012, 500
Market share share is closely monitored for signs of change in the competitive landscape, and it frequently drives strategic or tactical action." Increasing market share is one of the most important objectives of business. The main advantage of using market share as a measure of business performance is that it is less dependent upon macro environmental variables such as the state of the economy or changes in tax policy. In the United States market, however, increasing market share may be dangerous for makers of fungible and potentially hazardous products such as medicine, due to a US-only legal doctrine called market share liability.