Planners might be forgiven for sticking to media formats they know and trust in tough economic times. However, the variety of imaginative and unusual outdoor formats on the market offer flexibility and a level of targeting that typical six-sheet or 48-sheet campaigns may struggle to emulate.
James Copley, UK managing director of Kinetic, says whether the outdoor specialist uses niche out-of-home media depends on "how good the perceived audience is".
"Some campaigns need to reach as many people as possible, and then we look at a number of formats and environments," he says.
"But, for some campaigns, we just use a niche format, such as petrol pumps. Some brands might not want to be associated with certain niche formats, but for other brands and briefs, they're perfect."
Jodie Hall, associate director at Posterscope, agrees: "The main thing is to put insight at the heart of planning and then choose the medium that is right for the client and ensure the creative is relevant."
While established media owners such as Clear Channel and JCDecaux provide proof-of-posting to show agencies their campaigns have been executed as planned, accountability can be a major issue with niche sites.
Copley says clients sometimes worry that ads are in the "right place for the right amount of time", but believes niche media owners are becoming more reliable. Many niche formats are not yet covered by Postar, but more will be included when the updated version of the audience measurement system launches in 2010.
Unusual client solutions can also add PR value to media plans. For example, part way through this year's Brit Awards ceremony, the creative on Ocean Outdoor's St Paul's Church wrap on the A4 in Hammersmith was changed to congratulate the Kings of Leon for winning the award for best international album, as part of a campaign booked by Manning Gottlieb OMD and Posterscope.
DJ Johnny Vaughan noticed the switch and talked about it on his 95.8 Capital FM radio show the following day, exposing the campaign to his 981,000 listeners.
In this way, niche outdoor campaigns are often useful for creating column inches and talkability, according to Simon Jenkins, strategy director at MPG.
But the value of PR generated from specials is difficult to quantify, and Copley is keen to distinguish novelty stunts from regular niche campaigns.
He says: "Outdoor planning is about who you reach, the environment you reach them in, and the message you are trying to get across. It ultimately boils down to the audience."
The taxi advertising market offers clients a range of opportunities to reach high-end audiences in an environment with an average dwell time of 20 minutes.
Taxi Media, which Taxi Promotions bought from Clear Channel last week, has the largest fleet, while Ubiquitous, Taxi Promotions, Transport Media and Cabvision offer alternative taxi advertising options.
Traditionally, cabs are either fully wrapped with an ad, known as a livery, or have ads down either side of the vehicle, known as supersides.
Most contractors also offer special builds. For example, celebrity heiress Paris Hilton was driven around in a pink Taxi Media cab booked by Kinetic to promote her new ITV show, Paris Hilton's British Best Friend.
Inside the cabs, ads can be booked on the flip-down seats and on digital screens. Cabvision offers digital advertising, either via a dedicated TV channel or as spot ads among third-party content, while Taxi Media's screens do not show third-party content, giving clients exclusive access to the audience. However, agencies believe media owners could do more to acknowledge the variety of demographics of people who travel in taxis.
Arum Nixon, associate director, radio, TV and press at MediaVest, says: "Although cabs are seen as a way to target an affluent audience, focusing on this aspect undersells the opportunity. Taxis should take a leaf out of buses' book and push the broadcast benefits and high-street coverage far harder."
Cost: From £230 per taxi for a one-month taxi advertising campaign
Advertising in hospitals offers a range of niche advertising opportunities. In addition to the long-standing practice of giving gift boxes to mothers after they have given birth, many maternity waiting rooms now have digital out-of-home advertising in the form of Baby TV.
Baby TV screens, which are installed in more 100 hospitals, carry advice and information for pregnant mothers and their partners. The ads usually come in the form of infomercials - for example, car seat manufacturers explaining how to fit car seats - and are booked by agencies or directly by clients.
Meanwhile, Lighthouse Advertising, which launched in January with the British Heart Foundation as its first client, offers six-sheet advertising in 42 NHS hospitals, equivalent to 15 to 20% of the UK's NHS Trusts.
The ad sites target day-patients, visitors and staff in the public areas of hospitals, and are not located in wards or treatment rooms. All ads are carefully vetted by Lighthouse and the hospitals concerned. Alcohol, baby milk formula (for 0 to six months), tobacco products and funeral directors are not allowed to advertise.
However, buyers and planners must make sure the hospital environment is right for their brand. Ivan Clark, head of digital and creative solutions at Kinetic, says: "There is a reason why hospital audiences need to be protected. As a planner, you want the audience to be in the right frame of mind."
Cost: Baby TV spot ads from £4,100 per month and infomercials from £5,900 per month
Advertising is increasingly found in schools and colleges, as well as university student unions.
In primary schools, agencies can use postcards and colour-in worksheets to target five to 11-year-olds and their parents. Posterscope used postcards for its client Disney to promote the release of High School Musical 1 and 2.
Ten Nine offers six-sheet posters in high-traffic locations in secondary schools, colleges and youth clubs, as well as experiential activity such as postcards, leaflets and flyers. Clients including the COI, Unilever and Adidas have used Ten Nine's portfolio to target children and their parents.
Meanwhile, SubTV offers clients the opportunity to target students in student union bars. Students are increasingly attractive to advertisers due to their disposable income, and clients can sponsor content or buy spot ads on SubTV's digital screens. Posterscope research has shown that students view these screens as TV sets and are as receptive to their advertising as they are to TV ads.
Ads in schools and colleges often create a buzz in social groups, adding extra value to clients' campaigns. Jessica Armstrong, client director at Posterscope, says students and schoolchildren are more likely to talk about ads they are exposed to at university or school than those they see at home.
Cost: Ten Nine's bespoke campaigns with up to 800 panels cost £195 per panel per fortnight and its national network of 600 panels costs £117,000
Nigel Clarkson, sales and marketing director at Primesight Outdoor, says: "Niche opportunities are highly targeted, specific and, by definition, cost-effective. All four principles apply to Primesight's health club portfolio.
"It is nationally distributed, and hits 1.2 million health-conscious, upmarket ABC1s three times every week," Clarkson adds.
"The portfolio allows advertisers with smaller budgets, but a specific audience in mind, to put their message in the right environment with little wastage."
Sports clothing and equipment, healthy food and drink brands, and toiletries all work well in a gym environment.
Kinetic used health club screens, sponsored gym class leaflets and postcards to promote Sony Walkman phones, targeting people likely to be listening to music while they work out.
Cafés and washrooms also offer opportunities for ambient advertising.
Table Talk Media and Bag Media allow clients to advertise on the tables and paper bags of coffee shops, universities, service stations and pharmacies.
Lloyd Keisner, managing director of Table Talk Media, believes tables are a good medium for delivering informative campaigns, and that bag and coffee-sleeve products target the "on-the-go" market.
In addition to traditional ads on bar runners and beer mats in bars, clients can also target consumers in washrooms. Admedia offers ads on the back of toilet doors, which the company claims are "100% unavoidable", and High-Tech Media has 5,000 washroom panels in bars, pubs and golf clubs.
Cost: Primesight's health club six-sheets start at £240 for a two-week campaign
Research commissioned by Titan showed ad recall is three times greater in malls, proving why shopping centres have a regular place on media plans.
Titan and Clear Channel both offer extensive six-sheet opportunities in malls, while CBS Outdoor holds the contract for the mammoth Westfield centre.
However, the options only begin there. In September 2006, Limited Space launched its Adlift service, which consists of digitally printed HD vinyls applied to the entire surface of lift doors in 67 premium shopping malls.
Limited Space also offers wrapping the entire inside of the lift, sound effects, large-format panoramics and digital out-of-home screens.
However, smaller media owners such as Limited Space have to work hard to earn their place on media plans. Matt Gordon, managing director, says: "We place huge emphasis on transparency, research, accountability and client servicing. You must establish trust with your clients so they take that extra leap of faith."
Fitting rooms also offer a personal ad experience. Greg Ravilious, director of Fitting Exposure, which owns a network of A3 panels in the changing rooms of a number of high-street retailers, says fitting rooms offer "very precise, targeted campaigns". For example, a recent campaign for MTV show The Hills targeted females aged 16 to 30 through a changing room campaign in branches of New Look.
Cost: £56,500 for Limited Space's two-week Premium Impact campaign, with distribution in the UK's top 30 malls, including Bluewater, Lakeside, Bullring and Westfield Derby. Tailored/broader campaigns available on request
In Your Space moves away from traditional bus and cab advertising by offering ads on the backs and sides of delivery trucks across Europe, using frames and banners the size of 48 and 96-sheet billboards.
The 96-sheet trucks travel between cities, forming a "moving link" between urban campaigns, while the 48-sheet vans deliver to high-street stores, complementing 48-sheet billboards in towns and cities.
In Your Space prides itself on being one of the few ad companies that has a presence both on motorways, through its large trucks, and smaller roads, through its Sainsbury's delivery vans.
Jonathan Bramley, managing director, says: "Niche formats will continue to form part of advertisers' programmes as they target specific, often elusive audiences."
Mobile Media and Look Media also offer motorised out-of-home solutions. Their products can be used either to highlight one-off events and special offers from local businesses, or to launch new products.
Kinetic used Mobile Media to promote a sale at Pets at Home in Halifax and Posterscope has used mobile billboards to promote individual store openings.
Cost: £900 for 96-sheets, £600 for 48-sheets, £500 for backs of trucks and £400 for Sainsbury's vans, booked through In Your Space. All rates per vehicle per month, plus production costs
Some media owners stand out from the crowd because they are highly focused and have unrivalled expertise in a particular region.
Signature has about a 40% share of the billboards in Birmingham, with a concentration in the city centre, while Forrest controls 31% of all backlit screens in Scotland and owns a combination of backlit billboards, city screens and banners.
Roy Jeans, chief executive at IPM, says firms such as Signature and Forrest have bucked the "big four" domination trend in their respective regions by concentrating on areas they know inside out and are genuinely passionate about.
He says: "Signature arguably single-handedly kickstarted the backlit revolution a number of years ago, leaving Titan, JCDecaux and Clear Channel playing catch-up.
"Many regional media owners have built up a portfolio of quality sites in key locations. They compete on site quality, price and landlord contracts for new builds and they often have considerably greater success than their larger rivals by offering a more personal, local approach."
James Power, sales director, claims Forrest is the "single largest investor" in the Scottish out-of-home market. "We are the recognised market leader, not in terms of numbers, but in terms of quality," he says.
"Being 400 miles away from the decision-makers means we know we need to be markedly better than our larger rivals to stand out."
Cost: Forrest back lights cost £10,000 (96-sheets) and £4,000 (48-sheets) for a two-week campaign
Clients can look beyond the ubiquitous six-sheet to target consumers in the street, through products such as JCDecaux's StreetTalk, which allows advertisers to place messages on the sides of phone boxes.
Dave McEvoy, marketing director, claims StreetTalk phone boxes are "the closest thing you can get to guerilla-style marketing", and that they carry more "irreverent, urban, edgy and ‘street' creative work".
The film Adulthood was launched by Pathé and Kinetic on the StreetTalk network, JD Sports uses the phone boxes for trainers and urban wear, while the Government uses them for targeted drink, drug, crime and benefit fraud messages.
McEvoy believes that, since phone boxes are located where groups of young people congregate, they are "fantastic to get word-of-mouth brand advocacy going".
Elsewhere, AtmAd offers targeted ads on 6,100 ATM screens on the networks of Nationwide Building Society, Royal Bank of Scotland, Tesco Personal Finance and Alliance & Leicester.
Richard Rowley, head of media sales at AtmAd, says the economic climate has pushed accountability to the top of customers' priorities, and claims an AtmAd campaign purchased with 50,000 transactions is guaranteed to be viewed 50,000 times
He adds: "AtmAd's ability to show ads at specific times of the day enables brands to ensure they are targeting the right people at the most relevant time. The Sun ran an AtmAd campaign on weekday mornings, which was the perfect time to influence which paper might be bought."
Cost: JCDecaux's 4,000 CTN access panels cost £250,000 and its 2,000 Proximity access panels cost £200,000. Both rates for a two-week campaign