This is according to the measurement firm Verto Analytics, which monitored a panel of US adults who use personal assistant (PA) apps on their mobile over the course of a year and found no increase in the numbers using them.
In May 2017, 71 million or 44% of US adult smartphone owners used a PA app – the same as in May 2016 – but usage has been steadily declining since it hit a peak of around 88 million people in November 2016. However, in the same period, time spent on PA apps has more than halved.
Apple's Siri remains the most popular assistant despite a year over year decline in users of 15%. For its 7.3 million users, fewer now consider it a necessity, as daily users as a percentage of total monthly users fell from 21% to 11%.
"Despite all the hype, the take-up of personal assistant apps is spotty and sluggish and has yet to gain a sturdy mass-market foothold," said Hannu Verkasalo, CEO of Verto Analytics.
However, for Amazon, this has meant big gains for its flagship Echo device, whose operating system Alexa has enjoyed a 325% year on year increase in monthly unique users, growing from 0.8 million to 2.8 million users in the US alone.
Elsewhere, Microsoft's Cortana assistant, which is integrated with Windows phones as well as the desktop operating system and web browser, has seen a 350% jump in usage, to 0.7 million users. In addition, both have seen significant increases in stickiness (daily users as a percentage of total monthly users).
Verkasalo noted the shift in behaviour to home-based devices, adding that the report is "a reminder that usage of AI-driven apps and services is in its infancy as consumers are still exploring how to use them as replacements for search and other familiar online activities."
Yet he also noted that an analysis of the apps people use immediately before and after a PA app, suggested that the most common use cases are navigation or entertainment searching.
In addition, the study also found that the typical PA app user skews towards older women, so much so that the 1.5 hour per month 'superuser' is a 52 year-old female, well outside of the typical early adopter mould.
Data sourced from Verto Analytics; additional content by WARC staff