Since the introduction of the first iPad in 2010, Apple Inc. (NASDAQ:AAPL) is the king of the global tablet market. During the third quarter of 2010, the Cupertino based tech giant held a 93 percent market share based on data from the IDC.

iPad Mini

The emergence of competitors such as Samsung’s Galaxy Tab coupled with the availability of e-Readers from, Inc. (NASDAQ:AMZN), Barnes & Noble, Inc. (NYSE:BKS) among others, cut Apple Inc. (NASDAQ:AAPL)’s tablet market share by 20 percent in the fourth quarter of 2010 to 73 percent.

Based on data from IDC, Apple’s tablet market share continues to decline year after year. Apple’s 59.7 percent market share during the third quarter in 2011 declined by 9.3 percent during the same period in 2012 to 50.4 percent.

On the other hand, Samsung’s share in the tablet market is on the up. The South Korean company started shipping its Galaxy Tab during the fourth quarter of 2010. According to IDC, the company managed to capture 17 percent share in the tablet market.

During the third quarter of 2011, data from IDC showed that Samsung held 6.5 percent share in the tablet market. By 2012, its market share increased by 325 percent, having shipped over 4x as many tablets as 2011. This brought their market share up to to 18.4 percent as compared with the same period last year.

Samsung emerged as Apple Inc. (NASDAQ:AAPL)’s strongest rival in the tablet market as the company continues to develop and introduce new models including the Samsung Galaxy Tab 2, Samsung Galaxy Note and the Samsung Ativ Tablet.

Ryan Reith, program manager of IDC Mobile Device Tracker cited, “Samsung took advantage of an opportunity in the second quarter. The company offers a wide range of tablet styles across multiple screen sizes and colors; this clearly resonated with more buyers this quarter. Its growth to 18.4% of worldwide market share during the quarter represents the first time a competitor has attained this level of share since the original launch of the iPad.”

Based on the IDC data, it is clear that Apple Inc. (NASDAQ:AAPL)’s share in the tablet market is going downwards while Samsung is going upwards.

IDC tablet research director Tom Mainelli explained that Apple’s consumer and commercial shipments declined during the 3Q 2012. He said, “We believe a sizeable percentage of consumers interested in buying an Apple tablet sat out the third quarter in anticipation of an announcement about the new iPad mini. Now that the new mini and a fourth-generation full-sized iPad are both available, we expect Apple Inc. (NASDAQ:AAPL) to have a very good quarter.”

He also emphasized that the $329 starting price of the iPad Mini is “relatively high”, which provides Apple’s competitors “plenty of room for Android vendors to build upon the success they achieved in the third quarter.”

There is a great possibility that Apple Inc. (NASDAQ:AAPL)’s rivals would continue to bite its share in the tablet market. The price of Google’s Nexus 7 starts $199. The search engine giant is selling almost 1 million units every month. Amazon is also selling its Kindle Fire for $199.

According to IDC, manufacturers shipped a total of 27.8 million tablets during the third quarter of 2012. Apple and Samsung shipped 14 million and 5.1 million respectively. Other competitors including, Inc. (NASDAQ:AMZN) shipped 2.5 million, Asus 2.4 million and Lenovo 0.4 million.