IDC has been watching the growing popularity of the smaller, lower-priced tablets.

It found that one in two tablets that shipped this quarter had a screen measuring less than eight inches. It figures this strong trend is going to continue - strongly enough, in fact, for it to tickle its prediction of how many tablets in toto are going to ship this year and through 2017.

It upped global shipments this year from 172.4 million units to 190.9 million.

By the end of 2017 it figures annual tablet shipments will top 350 million, at an average yearly increase of 11% between now and then.

Analyst Jitesh Ubrani said, "Vendors are moving quickly to compete in this space as consumers realize that these small devices are often more ideal than larger tablets for their daily consumption habits." So much for Steve Jobs and his nine-inch ideal.

Of course Apple does have the iPad mini but Jobs wouldn't be too pleased with the rest of IDC's predictions because it expects Android tablets' market share to expand at the expense of Apple's and hit 48.8% this year, up from the old estimate of 41.5%, with Apple slipping from 51% last year to 46% this year.

Eventually, it says, both are going to lose share to Windows 8-based tablets, which should grow from 1% of the market last year to 7.4% in 2017.

The researcher says "Microsoft's decision to push two different tablet operating systems, Windows 8 and Windows RT, has yielded poor results in the market so far. Consumers aren't buying Windows RT's value proposition, and long-term we think Microsoft and its partners would be better served by focusing their attention on improving Windows 8. Such a focus could drive better share growth in the tablet category down the road."

It expects Windows RT growth to remain below 3% between now and 2017.

It also believes that pure e-readers - having peaked at 26.4 million units in 2011 - are on the decline because of low-cost tablets and expects a permanent decline in 2015.