eMarketer: Who can challenge the iPad?

Five years ago, there was no concept of iPad and tablet computer, but today, tablet computer has become a device that people are vying to own. According to IHS iSuppli, iPad accounted for 62% of global tablet shipments in 2011.

Amazon's Kindle Fire was released during the 201 holiday season and met analysts' expectations, accounting for 14% of shipments in Q4 2011. In the fourth quarter, Amazon shipped a total of 3.9 million Fire tablets, accounting for 6% of the full year.

iSuppli believes that Apple's own iPhone 4S may have diverted some people who were planning to buy iPads, especially considering the upcoming release of iPad 3. iPad 3 will undoubtedly continue to be popular, and Amazon and its peers will obviously have to work harder to maintain their market share.

eMarketer predicts that the penetration rate of iPad in the United States will double from 12% of Internet users to 22% between 2011 and 2013. However, the tablet share of iPad will drop from 83% in 2010 to 68% in 2014.

eMarketer believes that the number of tablet users in the United States will grow significantly, reaching 5.48 million by the end of 2012 and doubling to 8.95 million by 2014.