• by Steve Smith  @popeyesm, November 21, 2011

More costly and decidedly less “personal” than a smartphone, the true reach of the tablet platform must be measured in usage rather than sales alone. With many devices like the iPad, Kindle Fire and Nook Tablet likely to be shared among family, eMarketer projects that the 10.8% of the U.S. population now using these devices at least once a month will grow to a 17.3% penetration in 2012.

The addressable base number of Americans engaging the platform will expand from 33.7 million this year to 54.8 million next year. The research aggregator expects strong double-digit growth in the tablet audience to continue for several years, achieving a 27.7% reach by 2014, or 89.5 million people.

While both Amazon and Barnes & Noble are staging full assaults on the tablet market this season, eMarketer still sees the field dominated by iPads for the foreseeable future, despite competitive erosion.

iPad users alone will comprise 41.9 million people next year and 60.8 million by 2014, the company projects. In other words, nearly one-quarter of the U.S. population will have access to an iPad in three years. In 2014, Apple will only see its market share reduced from 83% this year to a still-hearty 68% in the forecast period.

eMarketer also expects the average age of an iPad user to go down. Given its price tag, 55.5% of tablet users now are age 35 or older and only 32.5% are 18-34. By 2014, less than half of users (49.3%) should be 35 and up, while 34.8% of the young-adult demo will be tapping and swiping the mid-sized mobile devices.

While sharing is an important part of the tablet penetration equation now, eMarketer expects the devices to become more personal over time, and like smartphones, become tied to individual users.

In a separate research note from ChangeWave measuring consumer intent, that company says interest in the Amazon Kindle is unexpectedly strong. Representing “the most explosive development in the tablet market since the release of the original iPad,” ChangeWave’s survey of over 3,000 consumers found 22% of potential tablet shoppers ready to opt for the Fire, with 65% leaning toward the iPad.

The company says this is the first time any iPad contender has registered in double digits. ChangeWave adds that the expected success of the Fire will not diminish the iPad’s strength in the market. The Apple device continues to have very high customer satisfaction. Rather, the arrival of the Fire appears to be expanding the market for tablets.

In August, only 6% of consumers surveyed by ChangeWave said they were planning to purchase a tablet in the next 90 days, about the level of intent found for the previous nine months. But the new survey taken this month showed 14% of consumers now saying they plan to buy a tablet soon.