The only thing worth measuring

Bluetooth. Used massively by kids who don't have the mobile phone contracts to go spraying data, mms and email willy nilly from their phones. Dr Ian Wood talked about the way his kids use it at yesterday's MIPS.
My observations of kids - and many adults for that matter - backs that up. They get together in physical proximity and share pictures, music etc via bluetooth.
Which raises questions about how we monetise this. The usual 'stick ads all over it' kind of solutions get chucked around. They lead to the inevitable "But how do you measure it?"

Here's my solution: Don't.

We are getting increasingly hung up on trying to measure how 'engaged' users are, or the pass-on rate of virals (which at least make an effort to understand that the ad is the content and the content is the ad - rather than plastering interruptive ads over 'the content').

The only measure that's real is; does more of what you're selling get sold?
The rest is observing information flows.

Maybe where this leads us is to a place where the creator of the ad message (the viral, the content that carries the message in some form or other) gets paid an agreed sum for the research and the resulting creative that the payee approves and then a % cut of the uplift in sales (if any!) over the next 12 months (that's an arbitrary number of course - meant to indicate over a longer scale than the blitzkrieg of most 'campaigns'. DIY distribution follows a much less explosive, much more organic, pattern).

Imagine if that 'creator of the ad' is a 'user'. There's a disruption. Where everyone is a content creator now, so everyone is also a marketer.

Advertising paid on results? Advertising that anyone can do? Is this a model already being offered or adopted (and I'm thinking a little beyond straightforward affiliate marketing)? Tell us why it's never going to work - or where it has already?