If you gave a tablet to someone for Christmas or you received one, you were far, far from alone. Tablets are becoming much more pervasive in the world of Internet-connected devices. 

A new study from marketing firm eMarketer says there will be more than 1 billion tablet users in the world this year.

That’s nearly double the number in 2012.

However, the rate of growth is slowing.

Yet despite a slowdown in growth, tablet users will hit 1.43 billion by 2018. 

How does that number compare to PCs and smartphones?

  • Research firm Gartner projected 2 billion PCs were in use in 2014.
  • And eMarketer projected 1.75 billion smartphones in 2014

Despite the tablet growth, eMarketer cautions, don’t get too excited if you’re a tablet investor or manufacturer.

“The key takeaway is that growth in the global tablet-using population will slow dramatically in 2015 and continue to taper off,” eMarketer reports. “The total number of tablet users is expected to increase by 17.1% this year. While this figure is healthy, it pales in comparison with year-over-year gains of 54.1% in 2013 and 29.1% in 2014. By 2018, the growth rate for new tablet users worldwide will be just 7.9%.”

Companies such as Lenovo, the world’s top PC manufacturer, and Apple have made big investment bets that tablets will continue to increase in popularity.

But according to eMarketer, tablets are still seen as “luxury items.” That may lower tablet appeal in lesser developed countries.

Plus, as smartphones become more capable – and in many cases larger with bigger screens, tablets will face more competition as an alternative platform for communication, entertainment and computing.

eMarketer notes several areas of concern for tablet growth:

  • Tablets continue to be perceived as luxury items, both from a perspective of share of wallet and share of time spent with media.
  • Tablets face increased competition from smartphones and a widening array of connected devices, including phablets, wearables, connected TVs and dedicated gaming devices, particularly in late-adopting countries like Japan and South Korea.
  • The use case for tablets is not always clear, particularly in markets where smartphone and phablet usage is robust.

“The shared nature of tablets and increased competition from other connected devices reduce the likelihood that the tablet audience will match the size of the smartphone audience worldwide,” said Cathy Boyle, senior analyst at eMarketer. “The most limiting factor is the use case for a tablet: It is not as clear-cut or compelling as a communication tool—the core capability and use case for a smartphone.”

Where are tablets most popular?

China at 328 million by the end of this year, eMarketer forecasts.

The U.S. will be far behind in second place at less than half that total. 

But don’t dismiss tablets as a fad.

Concludes eMarketer: By 2018, “nearly 20% of the world population will use tablets regularly.”