Yesterday, on their Webmaster Blog, Google announced that starting on April 21 it “will be expanding [its] use of mobile-friendliness as a ranking signal. This change will affect mobile searches in all languages worldwide and will have a significant impact [on] search results. Consequently, users will find it easier to get relevant, high quality search results that are optimized for their devices.”
This isn’t a surprise. In January, Google began pushing out warnings via Google Webmaster Tools to sites that offer poor mobile experiences. Before that, on October 29, 2014, they announced the new capability of tracking mobile usability within Webmaster Tools. Google defines a mobile-friendly site as “one that you can easily read and use on a smartphone, by only having to scroll up or down.”
So pinch-to-zoom, unplayable content, slow mobile pages, etc., are all going to be red flags to Google, indicating that your site isn’t mobile-friendly.
If you’ve been ignoring your mobile site, now would be the time to reconsider. Google recommends using responsive design, though dynamic serving or separate URLs on a subdomain are also accepted methods of mobile design when implemented properly.