Usage of mobile internet is expanding rapidly, and Google has long been at the fore of that charge. With Google, one must always look for the ulterior motive, and I suspect that in this case it’s to consolidate their stranglehold on mobile search – in the U.S. Google owns about 65% of the desktop search market, but over 95% of mobile searches are made with Google. They may even sell a few more Android phones. Seen in that light, it isn’t so strange that they’re encouraging people to create mobile-friendly sites, and their push does have the beneficial side effect of being good for everyone (except Yahoo and Bing).
To further their aim Google have created GoMo, a place where people can see what their site looks like on a phone and afterwards find ways to make their site mobile-friendly when they realize how bad it is. The “Reasons Mobile Matters‘ page has some particularly interesting statistics, notably that in 2013 (according to Google) more people will use their phone to access the internet than a desktop.
That said, people shouldn’t fall into the trap of simply porting the desktop site to a mobile version and hoping for the best. Mobile searches aren’t the same as those made from the comfort of a desk – people aren’t looking for the same things. Mobile searchers value local information that is timely. Those searches are often done on the spur of the moment to influence a decision that is only moments away. People seldom use their phone to research something they’ll be doing in two weeks, they’re looking up reviews for the movie as they’re in the theater parking lot, or trying to find the restaurant that’s closest to their current location. Keep that need in mind when designing a mobile website, otherwise it will be little more than a squandered opportunity.