Although Steve Jobs derided 7" tablets in public, he was apparently more enthusiastic about the idea behind closed doors. Jobs believed there would be a market for 7" slates, and boy was he right. According to the latest numbers from IDC, 50% of all tablets shipped this quarter have screen sizes under 8". This tweener tablet category is expected to continue growing, too. According to IDC Research Analyst Jitesh Ubrani, "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."
The "surge of smaller, lower-priced devices" has caused IDC to update its tablet forecast for 2013 and beyond. This year's total tablet shipments are now expected to reach nearly 191 million units, up 11% from the previous estimate. Steady growth is expected through 2017, when 350 million tablets are projected to ship annually.
IDC doesn't break down those shipment estimates by screen size, but it does make a few predictions about market share. No doubt due to the strength of inexpensive tablets like the Nexus 7 and Kindle Fire, IDC says Android devices will make up 48.8% of the tablet market this year, pushing iOS to second place with 46%. Apple enjoyed a 51% market share in 2012, and Android's gains reportedly came at its expense.
Windows tablets will purportedly garner 4.7% of the market this year and only 10.1% by 2017. IDC's crystal ball shows Android continuing to lead iOS four years down the road, with both platforms losing about the same amount of market share to Windows.
Apple's 7.9" iPad Mini certainly fits the bill for a sub-8" tablet, but it's not nearly as affordable as 7" devices like the Nexus 7, which starts at only 200 bucks—$129 less than the base Mini. There are no Windows tablets in the 7" range, but HTC is reportedly working on one that will run Windows RT. I'd be curious to see whether such a device could inspire more interest than existing WinRT tablets.