The Co-operative Group has partnered with Mars on a campaign using O2 Media’s location-based texting service, You Are Here, to offer customers a free Mars Triple chocolate bar.

Following the success of a trial earlier this year, in which The Co-operative gave away free bottles of Dr Pepper, the retailer is giving away free, limited-edition 52g Mars Triple chocolate bars to O2 customers within half a mile of around 2,800 Co-operative Food stores. The promotion runs from today until 5 October.

O2 customers who have opted in to the O2 More service will receive a text message offering them a free 52g bar at their nearest Co-operative store. To facilitate the scheme, virtual perimeters known as geofences have been set up around Co-operative Food stores. The service is triggered when a customer comes within the area bordered by one of the geofences, sending an MMS message with the offer and the address of their nearest store.

“Technology used in initiatives such as these is changing the way in which we interact with customers, and the forthcoming You Are Here campaign will allow us to engage directly with shoppers on a personal level,” says Helen Bridgett from The Co-operative Food.

O2 customers can sign up to be part of the scheme here.