The year 2016 has been a big year for mobile SEO, thanks to the successive updates that Google has made to its mobile SERP and search algorithms. The latest change that has made many marketers do a double take was announced by Google’s Gary Illys at PubCon last month. Google is going to have a separate “mobile only” index, which will become its primary index, and this is going to happen over the next few months.

The Method Behind Google’s Madness

Google’s spree of updates started when it said good-bye to the right column ads on its SERPs in February, and utilized the freed space to accommodate longer titles and meta descriptions. SEW reported in May that the page titles on Google’s mobile SERPs had from 55 to 78 characters. In August, the “mobile-friendly” label was removed from the SERPs, and Google started penalizing pages featuring intrusive interstitials. And then, there was the AMP update in September, when Google announced it would be displaying the  icon with AMP-coded pages on its mobile SERPs. AMP stands for accelerated mobile pages, a Google-backed technology that makes mobile pages load in a median time of 0.7 seconds.

And now, a dedicated mobile-only index is going to be the primary search index. It should not be a surprise if you’ve been aware of Google’s mobile-first strategy that it has aggressively pursued for at least the last couple of years. Most of the online traffic and all of the digital growth now comes from mobile. Desktops are fast becoming a secondary access point for an increasing number of users. Mobile has also caused voice searches to skyrocket, with the voice-based queries multiplying 35 times since 2008. These “natural language queries” are more diversified and longer than conventional search terms, necessitating longer page titles. So, there IS a method behind Google’s madness about mobile.

But why a mobile-only index? Google realizes that users behave differently on mobile than on desktop. They want the content to be served more quickly. They want to see directions or distance information for local search results. And yes, they want to see accurate results when they’re talking to Siri or voice-searching on Google. It is problem for Google to accommodate different user needs and search preferences with a single search index. A mobile-only index solves the problem.

How Mobile SEO Will Change in 2017

The mobile only index has thrown new challenges and opportunities at businesses and marketers. Many websites may see their mobile rankings nose-diving and traffic declining. Others may be able to work their way up to the top of mobile SERPs. In other words, you’ve got work to do.

The dilemma that many businesses will face is whether they should optimize for desktop or mobile. Should you have 68-70-char page titles that display on both desktops and mobile, or should you embrace the 78-char mobile SERP page titles? The longer titles (and meta descriptions) can accommodate long-tail and natural language queries as well as for your brand name, thereby improving your SEO rank. Moreover, conversion-focused websites may need to rid their mobile pages of full-page pop-up lead boxes in order to retain their mobile rankings.

If you are a small business, you might need to choose between mobile and desktop optimization based on how much of your traffic comes from these sources. However, competition may force big and small businesses alike to build dedicated mobile versions ( of their websites to retain their mobile traffic and rankings.

The AMP update also underlines the need to have a dedicated mobile website. AMP is an open source technology that developers and SEOs can deploy to dramatically increase their page speeds, and consequently, their mobile ranking and CTR. We can expect to see a revival of mobile-only websites in 2017.