How do you reach the largest number of people in the shortest possible time with your latest new offer or promotion? Easy. Send them a text or an e-mail.

Direct marketing via text message or e-mail already accounts for an estimated 13 per cent of the direct mail market, and is growing rapidly, as anyone’s e-mail inbox will show.

Robert Dirskovski, the head of interactive media at the Direct Marketing Association, says that electronic marketing is set to get more sophisticated with the spread of the new 3G generation of mobile phones which can handle graphics and larger chunks of text.

At least one company is also experimenting with using wireless technology to download details of promotions to the mobiles of passers-by. These e-messages will be generated from microchips contained in special sashes worn by marketing teams in high streets around the country.

Hypertag, the Cambridge-based company behind this idea, has already introduced advertising billboards equipped with microchips which can download information on to the mobiles of passers-by.

The advantages for companies of using electronic marketing are obvious. They can fire off messages at any time, reaching potential customers instantly without having to rely on the post. They can see how many people have opened messages or followed links to specific web pages.