As I reported at Search Engine Land, Google may add mobile UX as a ranking signal in the upcoming months.

Here is the statement Google sent me around my questions on mobile UX and ranking in Google:

Mobile-friendly websites provide a much better user experience for the mobile users. According to our studies, 61% of users are unlikely to return to a mobile site that they had trouble accessing from their phone. That includes sites that use fonts which are illegible on mobile, or sites where users have to zoom in or pan around excessively. Mobile is a very important area; the mobile device penetration is over 50% in the USA and most users use their device for browsing websites. Because at Google we are aiming to provide a great user experience on any device, we're making a big push to ensure the search results we deliver reflect this principle. We want users to be able to enjoy the web wherever they are.

I bolded the part I want to highlight. This is a Googley way of saying, we are working and looking into how to add user experience on "any device" (i.e. mobile devices) into the ranking algorithm.

In May, Google told us that they can now render the full final page and proved it with a new fetch and render tool in Google Webmaster Tools. Webmasters actually confirmed it based on their access logs - so we know GoogleBot is seeing and rendering what users see.

So if your size is a bad mobile experience to users, GoogleBot knows. I'll call out Moz, since they won't care about being called out, they don't have a mobile web site. They mobile site is their desktop site. Here is a screen shot from my iPhone:

The navigation, images, content, etc are impossible to really interact with without zooming in and blowing up.

See, here is the desktop version:

On desktop it works fine but on mobile, it is hard to use.

Now, for my corporate site, I know it is not the best (new interface is coming soon) but it is incredibly user friendly for mobile users:

The desktop version isn't bad also (but we are tearing it down and doing a new design soon):

Google wants to make sure mobile users that go from their search results have a good experience on your site. Their first step was to demote non-mobile-friendly sites and now they are looking into how those mobile web sites render for real users and if they are indeed mobile-friendly.

When is this coming? Who knows but I'd prepare now.

Forum discussion at Google+.