NEW YORK (CNNMoney) -- The proliferation of tablets from Apple, Motorola, Samsung and Research in Motion is making for a crowded market -- and it's one that will be worth tens of billions in four short years.
Research firm Strategy Analytics said in a study released Tuesday that the global tablet market will grow to $49 billion in revenue by 2015, with 150 million units sold worldwide.
That would make tablets the third-largest consumer electronics category, behind only TVs and PCs.
Market estimates vary between firms, however. And the Strategy Analytics estimates are actually among the most conservative.
Earlier this month, a Gartner study predicted global tablet sales will reach 294 million in 2015, for $77.4 billion in revenue. In a separate survey, Forrester said it expects 82 million people will be using tablets in the U.S. alone by 2015.
Since Apple kicked off the tablet craze last April, several competitors have jumped into the fray.
The first to dip its toe into iPad-dominated waters was Samsung, which released its Galaxy Tab in fall 2010. Next up was Motorola Mobility's (MMI) much-hyped Xoom, which came out in February and was the first device running on Google's (GOOG, Fortune 500) tablet-optimized Android 3.0.
The newest tablet is Research in Motion's (RIMM) BlackBerry PlayBook, a 7-inch device released on Tuesday. Hewlett-Packard (HPQ, Fortune 500) plans to charge into the market this summer with the TouchPad.
Last week, Gartner released a study breaking down tablet forecasts by operating system.
In 2015, Gartner expects the three biggies in the space to keep the lion's share of the market. Nearly half of all tablets will run on Apple's iOS (read: the iPad); Google' Android will comprise about 40%; and RIM's custom QNX software will be a distant third at 10%.
Karan has made the decision to step down from her role as chief designer at Donna Karan International, but she'll remain an advisor to the brand. More
The Brazilian and U.S. economies are the hemisphere's two biggest. More
Starting next year, MasterCard will allow you to verify online payments with a facial scan or a fingerprint. More
Three powerful business lobbies push back against President Obama's overtime rule changes that would effectively offer overtime protection to millions of additional workers. More