As the number one 'teen and tween' brand in the US, twins Mary-Kate and Ashley have been described by The Hollywood Reporter as the most powerful young women in Hollywood.
Their book series tie-in with their two hit TV series, which are broadcast in 57 countries.
To support the launch on 18 March, HarperCollins hired mobile marketing agency Aerodeon, to harness the power of text messaging among young girls.
To raise awareness of Mary-Kate and Ashley books and drive sales through a medium young girls find comfortable and entertaining. To generate word-of-mouth.
Strategy and Plan
In what is believed to be a first for a UK publishing house, the main thrust of the PR activity centred on a text messaging campaign. In March, HarperCollins entered into an agreement with teen title Sugar to send the magazine's database of 40,000 seven to 16-year-old texters an SMS about Mary-Kate and Ashley's book How To Train a Boy. Backed by some gossip about rap/garage collective So Solid Crew, girls received a humorous invite to text back for the twins' top tips for training a boy.
A week later, on 27 March this was followed by a message inviting girls to enter a prize draw to win Mary-Kate and Ashley merchandise.
In addition, HarperCollins has been running ads in Mizz, Top of The Pops Magazine and Girl Talk, to set up its own text club.
This activity has also been backed through more traditional PR channels, including sending review copies of the books to titles including Bliss and Girl Talk. In addition, the publisher has placed a series of Q&A sessions with the twins, with online book retailers, including BOL, Amazon and WH Smith.
Measurement and Evaluation
The hot tips text message gained a 15 per cent response rate and the SMS draw to win the Mary-Kate and Ashley goodies scored a 25 per cent response. Meanwhile, according to Aerodeon, the ads inviting youngsters to join the HarperCollins text club have already attracted more than 2,000 responses.
Less than a month after launch, the first six titles on sale have already topped 150,000 and look set to rise further.
HarperCollins children's books senior publicity manager Jo Williamson said: 'Tween and teenage girls are prolific text messagers, so this campaign has been a natural fit.'
Further texting activity is planned over the next month, in anticipation of the girls' arrival in the UK on 7 May.