Amazon caught the industry by surprise with the launch of its Echo smart speaker a little over two years ago. With the Fire Phone flop still fresh in everyone's mind, some in the tech community assumed the cylindrical digital assistant would was destined for the same fate but the reality couldn't have been further from the truth.

According to a recent report from market analyst Consumer Intelligence Research Partners (CIRP), Amazon has sold 5.1 million Echo devices in the US since launch and roughly two million units over the first nine months of 2016 (Amazon doesn't publish hardware sales figures).

The Amazon Echo launched in November 2014 on an invite-only basis before becoming widely available about six months later. While some may see it as little more than a glorified kitchen timer, the Echo (and its smaller siblings, the Echo Dot and Echo Tap, that Amazon launched earlier this year) can perform a number of useful tasks such as play music, control connected smart home devices, call an Uber, order a pizza from Domino's and get weather updates.

CIRP data indicates that more than 40 percent of Echo owners use the device as a speaker for listening to streaming music while roughly a third use it as an information provider responding to questions.

Amazon may have been first to market with its standalone digital assistant but it's no longer the only option to choose from. Google earlier this year launched its own voice assistant called Google Home and Apple is said to be building a "Siri speaker" to compete with those devices.