Q. What's black and white and read about all over?

A. The arrival of a Chinese panda. And PR giants can see rare opportunities from all that coverage...

It is the hugely expensive yet nutritionally useless diet which giant pandas feed on day and night – PR. The arrival of Tian Tian and Yang Guang at Edinburgh Zoo is as much a triumph for public relations executives as it is for conservationists.

The transportation giant FedEx is still basking in the hours of free advertising provided by television news channels when the "FedEx Panda Express" touched down in Scotland on Sunday.

The media was fed with images and background information about the pandas' in-flight meals and the specially-chartered Boeing 777 Freighter by Ketchum, a "public relations and marketing agency which specialises in corporate and product positioning".

The result was arguably the most successful corporate branding exercise since Oakley donated £280 sunglasses to protect the eyes of the Chilean miners rescued last year. That coup was calculated to be worth almost £1m in equivalent advertising time in the UK alone.

Once the pandas landed, they were handed into the care of Weber Shandwick, the "leading public affairs agency in Scotland". Lesley Clark, the company's vice president of international client service, no less, gave up her Sunday to email the press photos of the pandas settling into their enclosure. Weber Shandwick was hired to smooth the diplomatic track within the Giant Panda Partnership, a consortium including the Royal Zoological Society of Scotland, which owns Edinburgh Zoo, the Chinese Wildlife Conservation Association, the UK government and Chinese officials.

The only hiccup came when the New Tang Dynasty TV, which has exposed human rights abuses in China, claimed its accreditation for the press conference marking the pandas' arrival had been revoked after Weber Shandwick sent a list of attendees to the Chinese delegation. The agency insisted it was a matter of space.

Mark Borkowski, the public relations consultant, said: "There has been hardly any negative coverage. It's a story driven by pictures of cuddly animals in a time of doom and gloom. It's the animal equivalent of David Beckham going to play for LA Galaxy." Possible PR ideas for the pair include meeting the Duchess of Cambridge and predicting the winner of the Euro 2012 football tournament.