Separate 'Mobile Only' Index to Disrupt Results in Coming Months
The big news this month came out of the Pubcon 2016 presentation by Google's Gary Illyes, where he announced the launch of a separate Mobile Only index that is expected to roll out to the search results within "months". There has been talk of a separate mobile index since September 2015, but it has been viewed as only an experiment to this point because it goes against Google's very public goal of maintaining only one index for both mobile and desktop results. However, that goal seems less viable as mobile devices get more advanced and further and further away from the desktop experience, which is where this new mobile only index comes back into play.
To be clear, when this index rolls out it will change things drastically. Up until now, Google has been using the desktop version of a page for ranking signals on both mobile and desktop devices. Once those desktop signals are eliminated the mobile results will be turned on their heels. This shift makes mobile ranking signals absolutely vital to get correct and error free prior to this shift so that you can move up in the rankings and not down. Here's a quick look at the mobile ranking signals you want to be sure are in place sooner rather than later:
Responsive Design
AMP optimization in place
Fast loading pages
Error free pages
High quality content that fulfills the need of the user
Beware All Non Responsive Sites - It's also worth noting that if you're using .m or .mobi (instead of responsive design) for your mobile website then this shift could mean a BIG drop in rankings even if you're using canonical tags correctly because your link equity isn't going to be fully moved over to the mobile index. Google is still trying to figure this out and you can see that in play within this thread here.
And here are some resources you can leverage to audit your website for mobile usability, AMP optimization, page load times and more:
