April 08 2010 2:00 PMThere used to be a time when companies considered just customers and non-customers. You either bought the product or you didn’t. But it’s not that black and white any more. We now, of course, have to consider the non-customers who might be thinking of buying as well as the customers who might be thinking of leaving. And of course every other shade of grey in between. It’s complicated, but the sophisticated marketers of today know that their activities need to be geared up to suit potential customers at all stages of the buying process. The top of the buying funnels gapes wider than ever and, at the other end of the scale, we are increasingly conscious of the subtleties of brand perception as a tool to improve customer retention.So I find myself annoyed at the activities of my local Costa coffee shop, which has begun, in accordance with company-wide policy, insisting on payment for use of the wireless internet: a Â£2.50 purchase for one hour, to be precise. [It’s not the expense that annoys me, by the way, but the inflexibility.]The shocking thing, however, is the attitude of the area manager, which appears to be to assume that the new scheme is working because people [myself included] are still buying coffee and working on their laptops. This is where the black and white comes in. They are not half the customers they were. They pay as much money. Possibly even more. But as soon as a better alternative comes along, they are more likely to go and use it. No serious marketer would suggest that sales are the only measure of the strength of a brand - particularly in the short term - but that seems to be their view. These days we need to know who are the advocates, who are the churners, who are the likely converts. We need to deal in shades of grey because - outside Costa Coffee at least - things don’t just come in black and white.