In the early days, the computer was a productivity device, a glorified adding machine designed primarily for business.

The web changed everything. It turned the PC into a social device for email, IM and Facebook. Of course, if the computer is social, the mobile must be ‘super-social’ as it’s the first personal, mass-market social medium.

So what does this mean for mobile search engines? Well, because your phone is always with you, entertainment search is more important than it ever was on the desktop. Last year, it was estimated that there were 27 million search queries a day across all major mobile search engines.

Thanks to iPhone and its knock-on effect among other vendors, we can expect a doubling or tripling of search volumes in the next couple of years. That’s a lot of searching. But what are people looking for?

Studies by Yahoo and Medio in 2007 found users were searching for entertainment above anything else, illustrating that mobile is not simply a mirror of PC search (where entertainment is not the dominant category).

While the meaning of ‘entertainment’ differs between people, it still boils down to what brings enjoyment, relaxation or provide an effortless way to catch up with the latest news or topic of interest. For one person it’ll be the latest sport blogs, for another it will be the latest Duffy video.

The other significant finding from these studies was in relation to location based search (LBS). The industry has long claimed that local search (finding your nearest pizza restaurant, etc) would be a dominant category on mobile – but this was not supported in either survey.  It is more likely that location will be less of a search category than a highly valued utility.

So where does ‘social’ come in to play? Well, mobile devices are social tools. The handset brand, ringtone, wallpaper and other features all say something about someone’s identity. Mobiles are now as much part of the youth segment’s social currency as clothes and trainers.

In a sense, they also use search to help them achieve the same social kudos: when someone searches for their favourite band, they want to be able to play a track, see a video clip and send the track to their friends or post it to their social network.

But this is not easy to achieve. Sharing web content is a painless experience on the desktop; we have two hands, a mouse and capable web browsers. It’s easy to copy a URL into an email or drag and drop it into a Facebook Wall to share it with friends.

On the mobile, however, browsers are more basic, with minimal copy/paste functionality. Few users take the time to set up email on their handset, and sending URLs in text messages to multiple recipients is not easy.

For these reasons, relevancy, ranking and algorithms on mobile need to be re-designed from scratch. Through the use of social scores discovered within each community, it’s possible to discover the most appropriate results to serve to the user. This can provide more relevant results, especially for entertainment-related content. It is no longer acceptable to repurpose web content built for the PC.

When you search for a video from your favourite artist, finding out you can’t view the video because your phone doesn’t support the file type is an unnecessary frustration.

Today, mobile search is typically used just once a week. Soon it will be five times a day. Making search social is the key to growing the category as a whole.