According to the International Data Corp. (IDC), worldwide shipments of smart connected devices grew 29.1% year over year in 2012, crossing one billion units shipped with a value of US$576.9 billion.

The market expansion was largely driven by 78.4% year-over-year growth in tablet shipments, which surpassed 128 million in 2012. Looking specifically at the results for the fourth quarter of 2012 (4Q12), combined shipments of desktop PCs, notebook PCs, tablets, and smartphones was nearly 378 million and revenues were more than $168 billion.

In terms of market share, Apple significantly closed the gap with market leader Samsung in the quarter, as the combination of Apple's iPhone 5 and iPad Mini brought Apple up to 20.3% unit shipment share versus 21.2% for Samsung. On a revenue basis for the fourth quarter, Apple continued to dominate with 30.7% share versus 20.4% share for Samsung.

Going forward, IDC expects that tablet shipments will surpass desktop PCs in 2013 and portable PCs in 2014. In 2013, worldwide desktop PC shipments are expected to drop by 4.3% and portable PCs to maintain a flat growth of 0.9%. The tablet market, on the other hand, is expected to reach a new high of 190 million shipment units with year-on-year growth of 48.7% while the smartphone market is expected to grow 27.2% to 918.5 million units.

From a regional perspective, the smart connected device volume in emerging markets grew by 41.3% in 2012 with the tablet volume growing by 111.3% and smartphone volume by 69.7% year over- year. Mature markets, on the other hand, grew by 15.6% and saw a huge plunge in the PC market in the year 2012. By the end of year 2017, IDC predicts that the tablet and smartphone markets will have a huge growth potential in the emerging markets.

During this time, tablet unit shipments are expected to increase by a factor of three with a shipment value of $125 billion dollars while smartphone unit shipments are expected to double and reach a shipment value of $462 billion dollars. Portable PCs, on the other hand will show a moderate single-digit growth while desktop PCs are expected to consistently decline year over year with almost no growth in 2017.

"In emerging markets, consumer spending typically starts with mobile phones and, in many cases, moves to tablets before PCs," said Megha Saini, Research Analyst for IDC's Worldwide Smart Connected Device Tracker. "The pressure on the PC market is significantly increasing and we can see longer replacement cycles coming into effect very soon and that, too, will put downward pressure on PC sales."

Looking forward, IDC predicts the worldwide smart connected device space will continue to surge with shipments surpassing 2.2 billion units and revenues reaching $814.3 billion in 2017.

"Consumers and business buyers are now starting to see smartphones, tablets, and PCs as a single continuum of connected devices separated primarily by screen size," added Bob O'Donnell, IDC Program Vice President for Clients and Displays. "Each of these devices is primarily used for data applications and different individuals choose different sets of screen sizes in order to fit their unique needs. These kinds of developments are creating exciting new opportunities that will continue to drive the smart connected devices market forward in a positive way."