Cindy Krum’s keynote at EngagePDX a few weeks ago was both fascinating and a little disturbing:
[slideshare id=73116094&doc=mobile-first-keynote-v3-170314023128]
More detail can be found in this post Understanding Mobile-First Indexing (2/3): The Long-Term Impact on SEO
Mobile-first indexing is not the same as Mobile-first design and making sure your site is friendly to mobile devices. The internet is expanding to the point where Google cannot crawl everything, and crawling is in itself inefficient. Indexing is moving to a place where there are no URLs and Google (or Alexa, or a similar device) will tell you the answer to your question regardless of whether there is a URL associated with it. For marketers this means that we really need to be very clear about what question our content answers and structured data and schema.org matters again. See my recommendation to set your pages up with structured data and rich snippets and then my reversal when Google told us rich snippets were over. Tagging your content correctly will help our future AI overlords understand that we hope to be the answer chosen for voice searches and other searches.