Well they’ve really increased this as a search signal – sites that are NOT mobile friendly will now have a very hard time competing with those that are.
They’ve also updated their mobile friendliness test to make it more restrictive—it’s worth retesting your sites to make sure they still pass. Of course the best test is always the information displayed within Google Search Console which reports on the entire site, not just one page at a time.
The extra good news for those of you with mobile responsive sites is that any of your competitors who do not have mobile friendly sites will now suffer in their rankings.
One related point, there is a growing body of data that suggests this change also affects (in a smaller capacity) sites from normal desktops – that Google is prioritising sites that are mobile friendly on searches from ALL devices.
They haven’t confirmed that yet, so it’s not certain, but I am keeping an eye on it.
If you don’t have a responsive site for mobile devices yet and you don’t want to get caught out, please contact me and I can help make you a new, fully mobile complaint one.