Britain's Bristol International Airport ran a mobile coupon campaign to drive travelers into its recently refurbished Tax and Duty Free store.

The Tax and Duty Free store is now 50 percent bigger and offers a wider choice of brands at a fraction of the cost. The airport and its largest airline, easyJet, tapped mobile marketing firm Mantic Point for the easyJetText program.

"Mobile has proved to be an excellent way of reaching passengers on their departure day," said Simon Preece, head of retail and concessions at Bristol Airport. "Passengers who redeemed the easyJetText offer spent on average over 50 percent more than a typical Tax and Duty Free store customer."

Mantic Point is a mobile marketing company that helps travel brands produce loyalty and boost revenue by building mobile-enabled, personalized dialogues with travelers who are on the move.

With easyJetText, passengers opt-in to receive flight updates, reminders and special offers on their day of departure.

Passengers receive this information via text messages sent to their mobile phones.

EasyJetText lets advertisers target their offers to ensure their messages reach the right audience at the right time with minimal waste. This means that passengers only receive relevant offers that they like to respond to.

To entice people into the store and raise the amount spent, Bristol Airport gave opted-in passengers five Euros off of any purchase of at least 35 Euros.

The airport targeted its offer at international passengers travelling on certain routes.

The 160-character text message was sent to selected passengers about two hours before their scheduled departure time. This allowed Bristol Airport to capture people right when their interest in airport retail peaks.

Passengers were able to redeem the offer by showing their mobile phone to the cashier.

The cashier scanned the bar code to record that the passenger redeemed the coupon in-store and also recorded the flight number.

This information was then used to answer questions such as which route performs best, what the best time of day to make the offer is and which days perform the best.

"Analyzing this information on a weekly basis, we optimized the campaign by testing different calls to action and fine-tuning the targeting criteria to maximize the campaign's return on investment," Mantic said in a statement.