I felt this was a major news to share, as this new measure could severely prune the lot of styles, themes and templates for sale all over the internet, including Xenforo sites relying on monetization.
From Google's Webmaster Blog: http://googlewebmastercentral.blogspot.ca/2015/02/finding-more-mobile-friendly-search.html
"When it comes to search on mobile devices, users should get the most relevant and timely results, no matter if the information lives on mobile-friendly web pages or apps. As more people use mobile devices to access the internet, our algorithms have to adapt to these usage patterns. In the past, we’ve made updates to ensure a site isconfigured properly and viewable on modern devices. We’ve made it easier for users to find mobile-friendly web pages and we’ve introduced App Indexing to surface useful content from apps. Today, we’re announcing two important changes to help users discover more mobile-friendly content:
1. More mobile-friendly websites in search results
Starting April 21, we will be expanding our use of mobile-friendliness as a ranking signal. This change will affect mobile searches in all languages worldwide and will have a significant impact in our search results. Consequently, users will find it easier to get relevant, high quality search results that are optimized for their devices.
2. More relevant app content in search results
Starting today, we will begin to use information from indexed apps as a factor in ranking for signed-in users who have the app installed. As a result, we may now surface content from indexed apps more prominently in search. To find out how to implement App Indexing, which allows us to surface this information in search results, have a look at our step-by-step guide on the developer site."
From Copy Blogger:
"We actually got an explicit warning that a change to the algorithm was coming.
This was posted on February 26, 2015:
'Starting April 21, we will be expanding our use of mobile-friendliness as a ranking signal. This change will affect mobile searches in all languages worldwide and will have a significant impact in our search results.'
That date is important, but so is the word in bold.
My dictionary defines “significant” as “important; of consequence.” It’s the kind of thing you hear from a dead-serious parent.
In plain English: You better pay attention.
This update should surprise no one
The concern for mobile-friendliness is not a new direction for Google. As far back as 2011, they were declaring, based on the growing number mobile users, theZero Moment of Truth.
Since then, those mobile numbers have only increased, as I reported in an early 2015 article on adaptive content. And others are validating what we already know to be true.
According to Mitul Gandhi of seoClarity, 30 percent of total traffic comes from mobile, regardless of industry.
There is more on http://www.copyblogger.com/google-mobile-friendly/