Outdoor billboard advertising has increased customers’ intention to buy a line of Asda products by 31%, a study has shown.

The research commissioned by Primesight found the retailer increased sales of their ‘back to school’ range of lunchbox snacks after a two-week outdoor advertising campaign that targeted shoppers in close proximity to its stores.

A survey of shoppers showed that almost half of them had noticed the billboard after entering a store.

In response to the success of the billboard campaign the retailer has launched a similar two-week campaign for its ‘price-lock’ promotion.