The bus advertising business has progressed in leaps and bounds over the past decade, both creatively and in terms of the way it is sold and marketed. When the UK's bus transport infrastructure was privatised in the late 80s, the medium was being sold by civil servants working for either British Transport Advertising (London Transport Advertising in the capital) or by agents on behalf of the municipally run authorities in the regional conurbations.
So its emergence as a truly professionally run medium can be traced back just over a decade and the acquisition of LTA by the US outdoor advertising veteran Bill Apfelbaum - the same Bill Apfelbaum who has just ridden to the rescue of Maiden Outdoor, adding it to his Titan stable.
His UK operation, then called TDI, then moved to mop up BTA's bus contracts, and the municipal contracts too. For the first time, it could be marketed as a coherent national medium in a range of specially tailored packages - and revenues began to grow.
And that implies a substantial improvement on yield - because there's not much scope for increasing inventory. The number of buses in the UK is static at around 40,000 and in many of our towns and cities there has been a pronounced move away from double- deckers towards smaller vehicles.
That, in turn, is setting new challenges for the creative side of the medium.
Creatively, the most exciting development in recent times has been the emergence of the sorts of vinyl printing technologies that can see whole buses wrapped in stunning creative executions. It doesn't have to be a full wrap, of course. A popular option in recent times has been the Mega Rear, where the back of the bus is wrapped. And we've also seen vinyl used to break out of the conventional T format and spread the creative work across a greater area on bus sides. The printing technology has evolved to offer new options too, such as reflective and lenticular vinyls.
The number of wrapped buses out there on any typical week remains small, but this slice of the market makes a disproportionate contribution to revenues. The medium is now looking to make the jump to the next stage of its evolution - LCD panels.
Currently, these can offer moving words and relatively unsophisticated moving pictures comprised of pixillated graphics - but the race is on to offer something more akin to video pictures. The digital nature of these technologies will also, the market hopes, raise transport advertising to an even greater level of targeting precision. For instance, GPRS technologies can be used to change the creative execution, depending on which part of the route the bus is on.
The message can be tailored to the demographic profile of the area the bus is travelling through or, even more impressively, enable a retail advertiser to run a message that will only appear while passing rival stores.
Outside of the digital arena, the biggest news recently is the evolution of a new format tailored to the strength of the single-deckers now commonplace on most urban routes. Called Streetliners, these are 13-foot-wide sites along the bus sides.
MAJOR PLAYER: Viacom
WHAT'S NEW: LED special effects, digital screens, lenticular vinyl, reflective vinyl, streetliners
CASE STUDY - Dewyntners
Client: Dewynters - Cameron Mackintosh, Really Useful Group, EON
Productions, Billy Elliot, Chicago, Walt Disney, We Will Rock You
Media owner: Viacom Outdoor
Brief: Dominate the London landscape with theatre clients
Budget: £180,000 a year
Target market: Theatre-goers
Sector inventory used:Vinyl-wrapped buses in the livery of eight distinctive musicals in London. It was the first time TfL allowed London buses to be fully wrapped. The theatre buses are booked on routes that pass in front of the shows they are promoting.
Wider outdoor inventory used: Landmark sites, lift and escalator panels and four-sheets on the London Underground.
Other media used: Press and radio.
Client testimonial: Lesley Butterworth, media director,Dewynters: "The wrapped-bus format allowed us to reflect the individual productions. We are delighted to have been part of this very exciting first for London theatre."