I've read a quotes from barbarians on the site (and elsewhere) that have said things like "Just because an advertising vehicle is more trackable does not necessarily mean its more effective." and "I think the numbers become a big distraction, in a way."

Now I think that's an awesome perspective, which I totally agree with ... but my question is just how do you explain this to clients? How do you prove to them that a project has been successful? What are your alternative criteria for success?

@ Ollie - by saying it over and over, in every interview, until people start to listen and they think that way too. ;) it's a long process, and I definitely don't claim our clients all agree with us on it. But we like to default to telling the truth, even if it's unpopular (and man, that one is unpopular).

Thanks!