It's official: Facebook (NASDAQ:FB) is shuttering its virtual assistant, M. Launched in 2015, M was the company's response to the growing trend of virtual assistants. Facebook had hoped that M would be among the first generation of chatbots (supplemented by human guidance), which can help users accomplish a wide array of tasks. These same chatbots underpin Facebook's Messenger strategy, hoping to deliver customer service while enabling all sorts of other interactions between consumers and businesses.

There were two fatal strategic flaws with M, though: It was entirely text-based, and it was embedded within a messaging service.

Echo on a bookshelf

Stand-alone virtual assistants like the Alexa-powered Echo are driving the market forward. Image source: Amazon.

M couldn't hear you

All of the mainstream popular virtual assistants are voice-controlled, which has created a new interface paradigm for how people can interact with their devices. It's taken some time to get used to -- Apple's (NASDAQ:AAPL) Siri was the first to launch in 2011 -- but the trend is starting to gain critical mass. Amazon's (NASDAQ:AMZN) Alexa played no small part in that, and is now easily a leader in virtual assistants with its growing family of Echo devices.

Messenger exec Stan Chudnovsky told Recode last year that making M entirely text-based would remove one of the three steps necessary for a voice-controlled assistant to complete a task: recognizing the initial voice command as a task that the artificial intelligence (AI) can perform. Chudnovsky did say then that Facebook was planning on adding voice control at a later time once it had perfected the rest of the process. In other words, Facebook was simply missing a key part of the technological puzzle.

M wasn't readily available

That technological hurdle wouldn't be too hard to overcome over time, particularly if Facebook chose to license existing voice recognition tools from another company, but embedding M entirely in a messaging service was also a mistake. People want voice-controlled virtual assistants to be readily available upfront, and don't want to go digging around inside other apps to access them. Making Echo stationary was key to its success: Alexa is just always there.

Don't just take my word for it. Accenture recently put out a report predicting that stand-alone digital voice assistants (those found in smart speakers) will enjoy considerable growth in 2018 compared to embedded voice assistants (those found in smartphones). Not only do consumers tend to use stand-alone virtual assistants more often, they're often more satisfied, according to Accenture. Furthermore, consumers that use stand-alone assistants end up using their smartphones less.

Facebook M was a text-based assistant that was embedded in a messaging app that was installed on a smartphone, so the social network was fighting battles on two fronts to grow adoption. Over two years after launch, M only made its way to about 2,000 test users in California, according to The Verge. The company says it will use what it learned to help develop other AI offerings.

Perhaps that includes those rumors that Facebook is developing a smart speaker or some type of video-chatting device (Cheddar just reported fresh rumors that the device will cost $499 and be called Portal).

John Mackey, CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool's board of directors. Evan Niu, CFA owns shares of Apple and Facebook. The Motley Fool owns shares of and recommends Amazon, Apple, and Facebook. The Motley Fool has the following options: long January 2020 $150 calls on Apple and short January 2020 $155 calls on Apple. The Motley Fool recommends ACN. The Motley Fool has a disclosure policy.