I’ve written a fair amount about “ultrabooks” here, a type of slim laptop whose specifications were set by Intel. (Surprise! One of those specs is an Intel chip.) To the extent this blog has an overarching suspenseful question, it has been, “What will my next major technology purchase be?” I prize portability, productivity, and affordability, and find myself wavering between tablet and laptop options. The ultrabook has long seemed tempting.

Yet it would seem that other consumers aren’t feeling the same way–at least to gauge from some lackluster numbers put together by IHS iSuppli (and spotted over at Cnet and elsewhere). At one point, IHS iSuppli had estimated that 22 million units would ship in 2012. It’s now revising its forecast down to a mere 10.3 million. 2013 could be a disappointment for Intel and company as well: IHS thinks only 44 million shipments will go out next year, down from a previously thought 61 million.

What’s the source of the holdup? IHS points to “nebulous marketing and unappealing price.”

Having now pored over a few YouTube ads for ultrabooks, I can see what IHS means about nebulous marketing. Intel is in a curious position–it doesn’t make the ultrabooks themselves, and its tag line, or one of them, is “inspired by Intel.” And yet this hasn’t been a problem for Google and its partners positioning and branding the Android operating system. An ad like this one lacks the coherent sense of branding, and suffers from an overall vagueness. Rather than simply listing “things you can do” with an ultrabook, Intel & co. ought to have put together some sort of single slogan emphasizing the power of its chip in a sleek, thin body.

(Then again, in Intel’s defense, I got a good smirk out of this Camelot-themed ad.)

The argument from pricing I find more surprising. After all, I’m weighing my potential ultrabook purchase against a potential MacBook Air purchase, and some ultrabooks can be as low as $700, while the Airs start around $1,000. IHS points out, though, that the $1,000-or-more price point is still too common among many ultrabooks, too. A boost in sales could arguably come with the introduction of Windows 8 this October. But ultrabook manufacturers who choose to support Windows 8’s touchscreen option will be adding 100 bucks to the cost of a device, probably. (See “An Ultra-cheap Ultrabook.”)

Despite these shortcomings, it’s somewhat surprising that ultrabooks haven’t taken off more, given that many argue they offer a better value, in some regards, than a MacBook Air.

We should bear in mind, finally, that IHS’s estimates should perhaps be taken with a grain of salt, given the difficulty of strictly defining what exactly is or isn’t an ultrabook. “It’s definitely not an exact science,” IHS’s Craig Stice told the WSJ. Arguably, the MacBook Air itself might fit the bill as an ultrabook, under a lenient definition–but IHS didn’t consider it as such for its report.