Apple may be working on a new 4-inch iPhone, dubbed the iPhone 6C by the tech press, for an early 2016 release date. An unusual move for Apple, no doubt, but judging by the demand for a modern iPhone with a "classic" form factor, it may turn out be the smartest thing Apple could do.

20 Percent Polled Like 4-Inch Screens

That's because in a recent poll by Piper Jaffray (via Apple Insider), a sizable portion of U.S. consumers said they considered the 4-inch size -- Apple's standard until the rise of the 4.7-inch iPhone 6 and the 5.5-inch iPhone 6 Plus (and its "s" model successors in 2015) -- to be an "optimal" smartphone size.

While the majority of those polled preferred either the 4.7-inch (31.2 percent) or 5.5-inch (27.2 percent) iPhone size, 20.3 percent said they preferred the 4-inch form factor of the iPhone 5s. The remainder of the 1,077 U.S. consumers polled, 21.2 percent, preferred a different screen size than any offered by Apple's iPhones, past or present.

The poll could be taken two ways. Consider that, according to mobile and web analytics from MixPanel, the iPhone 5s makes up a little over 20 percent of active iPhones in the U.S. That tracks with the Piper Jaffray preferred size poll pretty closely.

So when it comes to the 20 percent that prefer the old 4-inch screen size among iPhone customers, you face a chicken and egg explanation: Either about a fifth of Apple's customer base prefers the 4-inch size of their iPhone 5s handsets, or that portion of Apple's customers simply haven't upgraded to an iPhone 6 yet.

The first explanation suggests Apple is missing out on a sizable portion of customers who are holding on to their old iPhones because they don't like the new upsized models. A new, updated 4-inch iPhone would then be worth it, even just as a way of keeping a fifth of their customers happy -- and spending money on new upgraded iPhones.

Piper Jaffray's Apple analyst Gene Munster told Apple Insider he believed the second explanation to be the most likely case.

"We believe that part of the reason that over 20 percent of smartphone users say they still prefer a 4-inch screen size is they still have older model iPhones," wrote Munster. "When they upgrade to a 4.7-inch screen with an only slightly bigger footprint in the pocket, we expect those users would be converts to the larger screen size."

Suggesting that the large minority of iPhone users that haven't upgraded to an iPhone 6 or higher believe they like the 4-inch screen, purely because they haven't been enlightened by using a 4.7-inch iPhone is a bit patronizing. Not to mention it deemphasizes the stubbornness of some iPhone users, especially in older demographics, who remain loyal to Apple because they value simplicity and consistency over change and (too much) choice.

'iPhone 6c' Release Date, Price & Features Rumors

Even if Munster is half of the explanation, there certainly remains a market for a new 4-inch iPhone. Current rumors have it costing between $400 and $500 off-contract, as it's intended to take the place of the quickly aging iPhone 5s (and earlier) models.

The iPhone 6C -- a moniker that will almost certainly not become the official name at release -- is rumored to be a 4-inch iPhone in the premium metal-and-glass style of Apple's iPhone 5s, rather than the candy-coated plastic construction of the short-lived "c" series.

Analysts expect it to include some current-day flagship iPhone features, such as Apple Pay and Touch ID, but don't expect it to come with the latest 3D Touch feature.

As we previously reported, speculation about the possible new diminutive iPhone began when Ming-Chi Kuo, a respected Apple analyst for KGI Securities with a track record of accurate predictions released an investors' note saying he believed an updated, but downsized, iPhone was in the works for the first half of 2016.

Others agree that the 4-inch iPhone could be coming in 2016 but disagree with the timing. Everything in Apple's recent history indicates that launching an iPhone in the first half of the year would be out of step with its usual development cycle, which hinges on a September iPhone unveiling and subsequent release.

Munster, for one, believes a smaller iPhone wouldn't be a big enough deal to warrant disrupting Apple's development cycle, much less to merit its own special launch event by itself. However, as the Apple Watch was unveiled in the spring, Munster believes a new 4-inch iPhone could very well tag along with the launch of an Apple Watch 2.