Clothing retailer Gap delivered 2.5m mobile ad impressions in just over two weeks through a campaign that combined traditional display advertising with geo-fencing technology.

Display ads were placed at transport locations, including bus stops, in New York, San Francisco and Chicago.

Ad agency Titan then created a geo-fence around these, which served an ad through Zynga’s Words With Friends app that included a coupon for $10 off a $50 purchase.

The mobile ads ran on Words With Friends from February 20 to March 6, and achieved a CTR of 0.93% – more than double the average CTR for mobile ads.

Taken from TechCrunchGap said the ads were a good way to incentivise shoppers to come into the store immediately after they had seen the initial brand message. 

But in truth the higher than normal CTR is probably skewed as consumers were incentivised to click on the ads. It would be interesting to see stats on the number of people that actually redeemed the vouchers.

The campaign is a clever way of driving engagement in a cross platform sense, and could also be used as a way to deliver additional content such as videos or competitions. But is this the best way to capture people’s attention when they’re in the right location?

It’s not clear whether the display ads were placed at locations near to Gap stores, but you’d hope so. Though displaying a traditional ad, then following up with a banner within an app is subtle reassertion of the same message – and one that’s incentivised – what happens if you don’t happen to be playing Words With Friends at the right moment? Has the opportunity passed?

Because of the comparitive CTR, we might see brands copy this method of delivering mobile ads – but in the short term at least, a focus on using QR codes and augmented reality in a smarter way is more likely to take up marketer’s time.