In postindustrial societies, not many days go by before a new kind of service emerges (at this site alone you'll find quite a few such as this, this and this.). The trend is reflected in both the public and private sector, and so naturally also in the advertising industry.
Services, if well designed, can offer dynamic and alternative touchpoints between the user and the brand, thereby allowing new kinds of interactions and experiences that are not necessarily so tightly controlled as ad agencies and brands traditionally prefer them to be.
To my knowledge, Nike is one of the front runners, when it comes to creating brand experiences through services but lots of others are exploring the field and coming up with interesting concepts, some of which are very basic.
A recent example that I like because of its relative absurdness is Broad Shoulders, which is a service provided by the mobile carrier Optimus to festival goers at music festivals in Portugal.
Basically, Broad Shoulders is made up of ten strong men who offer (female?) members of the audience the possibility to climb on their shoulders in order to get a better view of the concert or to find a lost friend amongst the crowd. Perhaps a bit sexist and possibly also annoying for those standing behind them but nonetheless, a simple way of addressing mobility without dealing wih complex technology.
Broad Shoulders is created by the ad agency Torke.Guerrilla Innovation