The campaign, "make a note", broke over the weekend, starting with teaser ads, or two-second "blipverts", and culminating in a roadblock on Sunday night in prime-time viewing.
The ads show Post-it Notes attached to various surfaces, reminding people that the old directory enquiries number 192 is closing. The notes feature BT's new 118 500 number, scrawled in typical office number-taking style, and appearing on everything from kettles and gates to buildings, under a microscope and on the Tyne Bridge in Newcastle.
BT is putting a massive outdoor advertising campaign into place throughout the nation so that, this morning, commuters in London, Glasgow, Manchester and Birmingham will be faced with 8,600 street-level posters; 3,900 giant poster sites; and 47 special-build sites with giant fibreglass Post-It Notes.
Five million pads will also be posted through people's doors, and the messages will appear on ambient media including pizza boxes, curry and Chinese takeaway bags, and in bars.
Amanda Mackenzie, director of marketing at BT, said: "We are trying to help people through all the confusion by getting them to make a note of 118 500.
"We're also making it very clear that 118 500 comes from BT, so that when customers make a choice, what they get from 118 500 is first-class quality, value and reliability, developed from 47 years of BT's Directory Enquiries experience," she said.
BT is the last of the major service providers to launch its advertising blitz prior to the closure of 192 on August 24, with The Number's 118 118 and Conduit's 11 88 88 already having several months' headstart.
Widespread confusion is predicted when the 192 service is closed for good. After August 24, people dialling 192 will hear a recorded message directing them to a freephone number, where they will be given one of the new 118 numbers to dial at random -- meaning that three calls will be made before the number can be found.
The campaign has been developed by St Luke's creatives, art director Vic Polkinghorne and copywriter Matt James. The television ads were directed by Leonard Dorfman through @radicalmedia. Media planning was through Rocket, with outdoor buying by Outdoor Connections and TV buying by the Allmond Partnership.
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