Advertising as a service

Here is a thought .. It is adapted from the idea of software as a service.

Consider that most elements today are being treated as a service

In software terms, What is a service(as opposed to a product)? I see it as an ‘ongoing relationship’ i.e. you buy software. Its a product. You sign up for the same functionality as a service.

Now advertising is ‘shotgun’ i.e. shoot at prospects, shout loudest that kind of thing

But initiatives like Google Interest based profiling change advertising from a product to a service (thinking from a software perspective)

thoughts?

I cant see any references to ‘Advertising as a service’ but may have missed it ..

Update:

Here is one. It refers to Blyk as an advertising as a service but does not explicitly define what Advertising as a service means. I agree Blyk can be an advertising as a service model

So, I see an advertising as a service as

a) An ongoing relationship between the provider and the advertiser

b) Based on preferences /profiles

c) Based on an agreement(for the lack of a better word) between the provider and the advertiser

d) The agreement will evolve as the service progresses i.e. a self learning service

e) The arrangement may span platforms(mobile web and TV) with probably mobile and web to be the leaders / early adopters

Not rocket science. All out there already for most part but I am interested in taxonomies/definitions