This is another sector of the out-of-home media industry that hardly existed a decade ago. Postcards have matured from an interesting, almost whimsical, opportunity filed under "ambient media" into an established and consistent media option, especially for advertisers wanting to reach younger consumers.
The pre-eminent postcard company in the UK is Boomerang Media, which launched in The Netherlands in 1992 and expanded into the UK two years later. It was the first company to establish credible distribution networks and provide media effectiveness figures for clients.
Boomerang's year-on-year revenue growth exceeded 100 per cent every year between 1995 and 2000, and it acquired its UK rival, Card Guide, in 2001.
Last year, the UK management led a buyout from the Dutch parent.
Boomerang produces about 100 million cards a year on average, distributing them to bars (such as the Slug & Lettuce and Pitcher & Piano chains), cinemas, health clubs, student unions and secondary schools. On average, 70 to 80 per cent of all cards are picked up per campaign.
Most campaigns offer some form of response rate. For instance, many will be double cards with a perforation fold separating the feature card from a second with a freepost address. You are invited to tear off the second card, fill it in and return it to the advertiser, enabling data capture as well as giving a yardstick as to audience reach.
Other calls to action, such as incentives to visit a website, can be used. A good response or redemption rate on a campaign would be around 25 per cent. And Boomerang is keen to point out it is included in the TGI survey.
More than a quarter of the cards in a Boomerang dispenser feature creative executions that the company terms "editorial" - cards without a commercial message but designed to amuse, entertain, prompt debate or simply maintain variety and diversity. In schools, the same proportion will be cards with educational value.
And despite their relative obscurity in the media world, postcards have a disproportionate pulling power in the creative community - largely, perhaps, because they offer such a pure canvas. Boomerang has an in-house design team but the company is regularly bombarded by ideas from up-and-coming designers, illustrators and photographers - having an execution accepted is good for their books. Boomerang sponsors the D&AD student awards and the postcard category is one of the most heavily supported in terms of entry numbers.
The market is now worth around £5 million a year and is a mature business now that growth has flattened out. The challenge for advertisers is to play to the sector's strengths as a tactile, eminently portable and collectible medium. Postcards are somewhat low-tech, obviously. You cannot digitise them, for instance, but you can keep interest alive in other ways - last year's campaign for the British Museum used lenticular techniques to create a moving picture effect.
MAJOR PLAYER: Boomerang Media
WHAT'S NEW: Websites and mobile technology used as response mechanisms
CASE STUDY - bmi
Agency: Mere PR
Contractor: Boomerang Media
Brief: Raise awareness of bmi's new route from London Heathrow to Mumbai, highlighting the diversity of the destination and encouraging regular use of the route.
Target market: Young, trendy, clubby Asian consumers and older Asians, who will use the route to travel to India to visit friends and family.
Plus a secondary non-ethnic audience of students, backpackers and independent travellers wanting to explore India. The key cities targeted were Manchester, London, Leicester and Glasgow.
Length of campaign: One month.
Outdoor inventory used: Double response postcards in universities, style bars, cinemas and health clubs.
Other media used: Sixty six-sheet posters placed in the female areas of private health clubs (women book 70 per cent of long-haul holidays), 350 A1 convexed lit posters in style bars nationwide.
Client testimonial: Nigel Dolman, senior manager, bmi long haul and regions: "We chose a Boomerang campaign to promote our Heathrow to Mumbai service because of its proven effectiveness in reaching the younger audience. It was important that we communicated our key messages to the younger market in a fun, impactful and visual way to stimulate a desire to visit the destination and travel there with bmi. Boomerang allowed us to do this while generating thousands of responses for data capture."