Gartner's recently released data on tablet sales in 2013 show that Google Inc.'s (NASDAQ: GOOG) Android was the most popular operating system for tablets. This was the first time that sales of such tablets surpassed those made by Apple Inc. (NASDAQ: AAPL).

There were 195 million tablets sold in 2013, and nearly 62 percent, or 121 million, of them were powered by Android. Apple's  iOS, previously the most popular OS for tablets, only accounted for 36 percent, or about 70 million, of the tablets sold. Microsoft Corp. (NASDAQ:MSFT) rounded out the list with Microsoft Surface tablets comprising only two percent of sales.  

Tablet Sales in 2013 Tablet Sales in 2013 Photo: Gartner

In 2012, Apple iPads accounted for 53 percent of tablets sold.

The good news for Apple is that the popularity of Android is divided among many different vendors. At 36 percent of the market, Apple iPads are still the most popular individual tablet. Samsung Galaxy tablets came in second with 37 million tablets sold, comprising 19 percent of the total.

Most popular tablets in 2013 Most popular tablets in 2013 Photo: Gartner

The strong Android performance was driven by “low-end, smaller screen” tablets, which suggest that a majority of mainstream consumers wanted a tablet that didn't come with the premium price that Apple charges. The sales were also due to the massive growth -- 145 percent -- in emerging markets where lower-cost tablets are in demand.

Gartner wrote that in the future, size and cost won’t be enough to drive sales, and vendors will have to focus on features. Apple will need to develop a low-end tablet to continue being competitive in the market, but it said Microsoft has the biggest challenge ahead.

“To compete, Microsoft needs to create a compelling ecosystem proposition for consumers and developers across all mobile devices, as tablets and smartphones become key devices for delivering applications and services to users beyond the PC,” Roberta Cozza, the research director at Gartner, wrote.

The report also noted that while tablets are the most popular “ultramobile” device, laptop-tablet hybrids were the fastest growing category in 2013. Cozza reported that consumers favored having a keyboard for productivity while enjoying the form factor of a tablet, and that these products will enjoy increased market share in 2014.