Smart door locks are readily available at your local hardware store (and of course, online) but they're not exactly flying off the shelves. Is it consumer awareness that's keeping buyers at bay? Security concerns? Or perhaps pricing?

According to one start-up, aesthetics may be a major hurdle.

Otto, a Bay Area outfit comprised of former Apple, Microsoft and Nokia employees, recently unveiled its smart home lock by the same name.

The first thing that you'll notice about the Otto is its lack of a keyhole and physical keypad. The device is largely designed to work by syncing with a smartphone although there is a digital keypad that can be used should you not have your phone handy.

Some will scoff at the idea of not having a key hole as a backup (a valid concern) although its absence does look great and reduces security concerns a bit (can't pick a key hole if it isn't there). Should the unit's battery die, there is a built-in back-up unit that'll power the lock for about a dozen cycles.

Clearly, Otto is trying to do for door locks what Nest did for thermostats. They've seemingly got the right team in place and the product certainly looks the part. The only issue, then, is the cost.

Otto's first smart lock will set you back a cool $700. For one door lock. Ouch. For that price, you could outfit an entire house with standard locks with loads of cash left over or even put other smart locks on your main doors with money to spare for security devices like, say, a Ring Video Doorbell 2 . But, the aesthetics...

Otto is now accepting pre-orders for its smart lock with plans to ship the first batch this fall.