Small screens, tiny batteries, a general air of nerdiness and no particular reason to exist: it's never been easy selling smartwatches and it's not going to get any easier anytime soon.
Samsung was first off the blocks this time around with the release of the Galaxy Gear, and has apparently shipped 800,000 of the smartwatch (although it's unclear how many it has sold). But despite plenty of rumours that they're working on rival timepieces, few of the other big players (Google, Apple, or Microsoft in particular) seem especially keen to join the smartwatch race, leaving it to startups, Kickstarter-powered projects and fitness bands to make most of the running.
The real problem with smartwatches is the lack of discernible interest from consumers, outside of niche (mostly sports) users. Of course, if you ask people what they want, it's well known they'll only ever demand a faster horse, so it's always how to gauge how consumer interest in nascent products and technologies will develop.
This Google Trends graph sums up that consumer apathy problem neatly. At the moment, the only people interested in wearable tech are the staff of the tech companies that are making it.
smartwatches smartphones
This Google Trends chart shows the relative interest in the terms 'smartwatch' in blue and 'smartphone' in red.
It's worth noting that I tried to create a similar Google Trends chart for the terms 'iPhone' and 'iWatch' but such is the difference in the scale of interest it just didn't work — and it's perhaps relevant that the iWatch rumours have dried up in recent months.
The same problems (and more) face other wearable devices such as Google Glass-style smartglasses: unless you wear glasses already, you probably won't want such headsets at all. And if you do wear glasses, you probably won't want to wear something so bulky and dorky — or, if you did, your friends, family and colleagues probably wouldn't be keen on having you hanging around looking like a bipedal security camera.
Some have tried to make a case for smartglasses in the workplace, but the real-life applications remain distinctly limited; and, for most use cases (taking or watching videos, for example), a smartphone can already do those jobs very well.

Before the iWatch: A history of smartwatches, in pictures

Before the iWatch: A history of smartwatches, in pictures
Before the iWatch: A history of smartwatches, in pictures.
Vendors are keen on wearable smart devices because they're worried about saturation in the smartphone market and low margins in the tablet world (and decline in PC sales). But can wearables really provide an alternative revenue stream worth having?
The current or next crop of wearable gadgets are mainly viewed as companion devices. That means either an additional cost for consumers — meaning they won't fly in developing markets or with price-senstive buyers elsewhere — or they'll end up being bundled with other devices such as smartphones or tablets for free. As a result, they'll only ever offer incremental revenue on top of smartphones, rather than being the brand new revenue stream that investors are craving.
It's tempting to see the smartwatch (and wearable tech in general) as falling into the same category as the paperless office and the cashless society: something that's always going to be just another five years away. But it's more likely that the smartwatch is running through the same cycle as the tablet did a decade ago: pretty much every tech company saw the opportunity but nobody could make it work until Apple built the iPad. Simillarly, all of the usual suspects have been building smartwatches for years without getting the package right.
Smartwatches and wearables could be running round that circuit for another five years yet before one company puts all the right elements together to create a must-have device. As with so much hardware in this market, much depends on what Apple decides to do.
But the biggest reason smartwatches will find the going tough in the short tem at least is that there's actually plenty of innovation still left in the smartphone.
Smartphone designs were much more excitingly polymorphous before the cold black slab of glass become the default imposed by the state of the art touchscreen model — think of all the amazing Nokia designs of yesteryear. Advances such as curved screens could rescue the smartphone from it's black mirror design doldrums.

Similarly, smartphone payments, imaging, and better battery life are areas with a lot of development work ahead. As such, the curved and flexible screens just entering the mainstream will be a much bigger deal for consumers than another wearable gadget they just don't understand.