Yet another reason you might want to consider going responsive instead
Pressure has been put on sites with what Google is calling "faulty redirects". These occur when a user on a mobile device requests a desktop page linked to on Google and is instead redirected to the site's mobile homepage. According to Brian Klais, CEO of Pure Oxygen Labs (a mobile marketing firm), retailers with faulty redirects will suffer in their Google rankings.
Google recommends webmasters follow the industry best practice of using responsive web design, namely serving the same HTML for all devices and using only CSS media queries to decide the rendering on each device.
Responsive website design offers the best solution
As Bill Siwicki points out on Internet Retailer, this might be a good time to consider going with a single responsive website instead of relying on separate mobile and desktop websites:
There is a way around this common problem: Instead of going mobile with an m-commerce site for smartphones, create a responsive web design site. In fact, that is Google’s No. 1 recommendation for businesses looking to optimize their sites for mobile devices.
Responsive design uses one set of web content and one code base to create a single site that renders differently to fit the size of the screen of any device, be it a desktop, tablet, smartphone or smart TV. Because a responsive site is a single site, it only has one URL per page; thus, there is no need to match desktop URLs with mobile URLs.
Bill has offered three excellent tools to test if your mobile website is meeting Google standards.
Free tools to test your mobile website
Klais’ firmPure Oxygen Labs has created three free web-based tools retailers can use to check their mobile sites to see if the sites comply with Google’s rules. They are Mobile Site Analyzer, Mobile Page Analyzer and Mobile Redirect Viewer, and are located under the Tools tab at PureOxygenMobile.com. A marketer can enter a page URL into Mobile Page Analyzer and in 10 seconds view a report on the page that indicates whether it meets 10 criteria to pass muster with Google. The tool breaks results down by iPhone, Android and BlackBerry mobile operating systems. A marketer can enter a group of up to 50 pages into Mobile Site Analyzer to view reports on all pages in less than 10 minutes. Mobile Redirect Viewer accesses a single page simultaneously emulating five user agents—desktop computer, Google bot, iPhone, Android and iPad. The tool produces a report that shows a marketer or webmaster how her site is responding to different devices, and whether redirects meet Google requirements, Klais says.