Research firm IDC has released its quarterly mobile phone tracker report, which reveals that the total worldwide smartphone shipments crossed 1 billion units mark for the first time. According to IDC, a total of 1,004.2 million smartphones were shipped in 2013, which is up 38.4 percent from the 725.3 million unit shipments in 2012.

“The sheer volume and strong growth attest to the smartphone’s continued popularity in 2013. Total smartphone shipments reached 494.4 million units worldwide in 2011, and doubling that volume in just two years demonstrates strong end-user demand and vendor strategies to highlight smartphones,” stated Ramon Llamas, Research Manager with IDC’s Mobile Phone team in a press release.

IDC claims that low-cost smartphone and phablets are the key drivers in smartphone shipment growth in the last two years.

“Of the two, I have to say that low cost is the key difference maker. Cheap devices are not the attractive segment that normally grabs headlines, but IDC data shows this is the portion of the market that is driving volume. Markets like China and India are quickly moving toward a point where sub-$150 smartphones are the majority of shipments, bringing a solid computing experience to the hands of many,” notes Ryan Reith, Program Director with IDC’s Worldwide Quarterly Mobile Phone Tracker.

Here is a look at the vendor specific smartphone shipments for the year 2013:

As you can see, Samsung remained the top selling smartphone vendor, followed by Apple, Huawei, LG and Lenovo. Lenovo’s growth is particularly interesting as it sells its smartphone in a very limited set of countries including China and India, which is a proof of how these two countries have started dominating the smartphone shipment numbers in the last few quarters.