Mobile Commerce – What You Must Do For Google

There are three things a retailer must do:

First, a retailer’s site must have what is known as a “vary header” that indicates user agent the mobile platform initiating a request; this tells Google that the content at the URL varies by user agent, Klais says.

Second, for desktop pages and mobile pages that correspond to one another, retailers must insert on the desktop page a meta-tag called an alternate tag that identifies the mobile version of the desktop page and the mobile URL, Klais says.

And third, to complete the loop, retailers must insert on the mobile page a meta-tag called a canonical tag that identifies the desktop version of the page and the desktop URL, Klais says.

via Mobile Commerce – Google cracks down on mobile laggards – Internet Retailer.