Site Not Mobile Friendly, You Won't Rank Well, According To Google.

Google has taken a strong stance on mobile SEO, announcing there will be demotions if your site is not mobile friendly or is misconfigured when it comes to being mobile friendly.

Smartphone users are a significant and fast growing segment of Internet users, and at Google we want them to experience the full richness of the web. As part of our efforts to improve the mobile web, we published our recommendations and the most common configuration mistakes.

Avoiding these mistakes helps your smartphone users engage with your site fully and helps searchers find what they're looking for faster. To improve the search experience for smartphone users and address their pain points, we plan to roll out several ranking changes in the near future that address sites that are misconfigured for smartphone users.

Read More here and at Search Engine Roundtable