Shoppers will have internet adverts displayed to them based on their offline shopping habits.

The new scheme is being developed by internet publisher Yahoo!, and customer loyalty scheme Nectar.

The two companies will link their databases in a bid to target consumers with relevant adverts, and to improve the tracking of the effectiveness of adverts, in persuading consumers to buy goods.

The programme, called Consumer Connect, will link the databases of both companies.

That way, Nectar's information can influence the results of the behavioural advertising system, that determines what adverts a Nectar user sees on pages whose ads are supplied by Yahoo!.

Though this is already common with online behavioural advertising, previous systems have not been able to use offline shopping data.