• by Laurie Sullivan  @lauriesullivan, June 27, 2011

eReader adoption rates have surpassed those of tablets, according to a Pew Internet & American Life Project report released Monday. Some search marketing experts believe the gap will widen as eReaders become more affordable and offer the most basic Internet-connected services for free.

The share of adults in the United States who own an eReader doubled to 12% in May 2011, up from 6% in November 2010. Kindle or Nook, both portable eReaders, allow consumers to download and read books and periodicals. Amazon on Kindle offers 3G connectivity for free. This is the first time since Pew began measuring eReader use in April 2009 that ownership of this device has reached double digits among U.S. adults.

Tablet computers designed for more interactive Web functions have not seen the same level of growth in recent months. In May 2011, 8% of adults reported owning a tablet computer, such as an iPad, Samsung Galaxy or Motorola Xoom. That percentage has only slightly risen from the 7% who reported owning this type of device in January 2011. It represents a 3 percentage-point increase in ownership since November 2010. Prior to that, tablet ownership had been climbing quickly, according to the report.

Similar to the need to segment mobile from computers in paid-search platforms, such as Google AdWords and Microsoft AdCenter, it will become increasingly important for marketers to segment eReader campaigns from those running on tablets once the engines offer the service.

Search on eReaders will become the device's most basic function, according to some experts.

"Clearly, eReader manufacturers like Nook and Kindle will bundle deep Web functionality to capture more market share because many people only want basic access to the Internet services, such as email and Web surfing," said aimClear Founder Marty Weintraub. "It's a no-brainer, really. Searches will increase for these devices across millions of books, and we can expect manufacturers to poach market share from devices like iPad."

Consumers have access to the Internet and search through eReaders, which are less expensive compared with tablets, less complicated to use, and book-centric for those who want the convenience of a digital device. The ability to access the Internet and search for information could keep eReaders "over the top" when it comes to adoption, Weintraub said, pointing to Kindle, which offers free 3G wireless connectivity.

Search marketers also can expect to see companies such as Adobe to segment eReaders from tablets in analytics packages to support campaigns, according to Tim Waddell, director of product marketing at Adobe. "We haven't done that yet, but it will be something we will need to address in the future because the engagement is quite different," he said. "We segment out mobile search already. It's quite easy to do. We will do the same thing for other devices as they become available."

Adults 18-65, Hispanic adults, college graduates and those living in households with income of more than $75,000 are most likely to own eReaders -- up from $30,000. One-fifth of recent college graduates own eReaders.

Similar demographic patterns exist for tablet adopters, although parents are no more likely than non-parents to own these devices. However, in the case of tablet computers, men are now slightly more likely than women to own this type of device.

Between November 2010 and May 2011, men had among the largest increases in tablet owners. Overall, the highest rate of tablet ownership falls among Hispanic adults and those with household incomes of at least $75,000 annually.

Other adopters include adults 18-29, those with some college or college degrees, and those reporting household incomes of $30,000 or more.

The survey -- which was conducted from April 26-May 22, 2011, among 2,277 adults ages 18 and older -- also reveals that laptops have become as popular as desktop computers among U.S. adults. As recently as November 2010, desktop ownership outpaced laptop ownership by 8 percentage points, 61% to 53%.

While the popularity of mobile devices continues to rise, eReader and tablet computer adoption levels among U.S. adults remain well below these tech devices that have been on the market longer.