Tired Metaphors I - The Purchase Funnel

I'm working on a different way of approaching the concept of the 'purchase funnel'. I don't know if I'm just bored of talking about it or whether it's actually an oversimplification people's behaviour. I'm almost certain, though, that there is a 'friendlier' way for marketers to conceptualise their customer relationships (or webmasters their site traffic for that matter).