Facebook borrowed the word friend and constructed an on-line social network around it, but since Twitter it is clear that the real currency is attention - and has been all along.
As a concept, Facebook friendship mimics the qualities of the real, face-to-face variety - things like trust, loyalty and support. But when a person's on-line friends come to be numbered in the thousands, it is difficult to see how those qualities can retain any real meaning.
Attention, on the other hand, is a much more malleable commodity. And it can be traded too - as I have just discovered in a New York Times article on the latest trends in on-line advertising. I say 'just discovered' despite the fact that I thought I understood how this stuff worked: for example you ask Google Translate to tell you the Greek for 'Does your hotel have a swimming pool?' and along with the answer Google obligingly provides you with ads for holiday resorts on the Peloponnese - except for the fact that since I'm already at the stage of asking the hotel about its facilities, I might have been more interested in travel insurance.
So it's kind of obvious and a bit simplistic - or so I thought.
When we go online we are giving things our attention and it is our attention that advertisers compete for, because once they have got it, there is the chance they can turn it to their advantage - or even sell it on. All the same, it came as something of a shock to learn of the degree to which my individual attention is being traded. When I search for something on Google (and it's not just Google by the way) it only takes a second or two for the results to be displayed but that is plenty of time for advertisers - or more precisely, software acting on their behalf - to bid for the right to stick an ad under my nose. The whole auction is conducted in a fraction of a second, with advertisers bidding not simply in response to what what I am searching for at that instant but on the basis of a profile that has been built of me over time. So it might go something like:
Google:lot#123456789:idomnivorist:dob27091949:session4102s:profile follows .. what am I bid?
The fact that I very rarely click on adverts (a fact that must feature quite prominently in my profile) no doubt makes me a less attractive prospect and advertisers might well decide to let me go by unmolested. However, the sight of a different type of on-line shopper heaving into view - one for example with an established tendency to make expensive impulse purchases - must liven up the proceedings no end.
The New York Times article includes a vivid illustration of the way things are going. Picture yourself walking along a city street, late at night, past advertising hoardings that are changing just for you.
No thanks ...