BT is offering free phone calls to East Anglian punters in return for them listening to a stream of adverts. The telecomms giant started the AdCall scheme at midday last Thursday in phone boxes in Cambridge, Ipswich, Norwich and Kings Lynn. A total of 340 phone boxes in the area have been equipped with the service. Most are located in Cambridge, where 175 of the 200 facilities in the town offer the freebie, a BT representative said. In return for listening to advertising spiel for 30 seconds, users get a free local or national call worth 10 pence. This amounts to 67 seconds for a local call and 43 seconds for a national call, on or off peak. Customers can choose to make a normal phone call or use the free service by pressing the "hot button" which connects them to the system. Kiosks have signs displaying that they are part of the scheme. Advertisers using the service include online auction house QXL, Mars and Fiat. AdCall was originally launched on the Isle of Wight in August. According to BT, East Anglia was chosen for the service because it provided a good mix of customers. In September BT started a pilot service based in Bristol and Newcastle called Freetime. Steve Davis, head of marketing for BT payphones, said of the Isle of Wight trial: "The response far exceeded our expectations, with more than 47,000 customers using the new service during the six-week trial." According to research by BT, most users of phone boxes in the UK are 16 to 24-years-old. 70 per cent of this age group use a payphone at least once a week. BT currently has 141,000 phone boxes in the UK. ®