Reproducing the magic of Search on digital OOH would be a huge communications, creative and technical challenge. It involved making 'dumb' digital screens smart, and - just like the app on smartphones - able to anticipate their audience's needs. Driving downloads and usage was a huge challenge, because changing people's habits is hard. While they're out and about, people happily look for information on their mobiles through browsers and apps. To persuade them to use the Google Search App instead, we'd need to show a compelling reward.

The real goal was more people using the technology more often. Outside 2.0 would only be a success if it increased downloads, trial and regular use of the app itself. The 2013 campaign (Google Outside 1.0) proved that digital OOH could change how people feel about the Google Search App. That was an important step, but what we really cared about was changing how people use it.

We took over 1,240 digital screens. Commuter press and mobile display ads ran in parallel so that we could be present throughout Londoners' everyday journeys. The digital screens created a city-wide presence that reached Londoners in different contexts and touchpoints, during their daily commutes, lunch hours and evenings out. So if it was evening and you were in East London, Outside 2.0 might suggest an Indian restaurant in Brick Lane and give you directions to get there. On a sunny Saturday morning near Regents Park, it might give you opening hours for London Zoo.

The effort was worth it. By delivering highly contextual and relevant content at every location, at any time of the day, the campaign truly cut-through and resonated with Londoners. We saw a huge payoff in terms of Londoners' response to the campaign, with unprecedented awareness levels and strong positive sentiments about the Google brand and the Search app.