Some people argue that a thin line separates being tough and aggressive and being rude but in my experience the line is not thin at all. However, there is no simple way of drawing that line; it's a bit like trying to describe an elephant which may be difficult in theory but easy enough as it approaches you.

Personally I can't abide rudeness; indeed as I get older I find it more intolerable. This came to mind when a long-term, albeit somewhat erratic customer, sent me a highly offensive e-mail littered with swear words. It could be argued that I should have ignored it and clung on to his business. Instead I sent a brief reply saying although I valued his patronage I had no intention of being addressed in this foul manner and would not respond to this kind of language.

The customer is always king but they need to act like kings to be treated as such.

And this works both ways because it is far easier to cut off relations with a rude supplier but more tricky to deal with rude customers or indeed the haughty and rude regulators who plague the catering business. Sometimes you just have to ignore your feelings and press on with these people but they never get the best out of the companies on the receiving end of this treatment.

At one extreme in my trade you hear tales of chefs spitting in the dishes of rude bosses and rude customers (I assure you this does not happen in my establishments) but more often you hear about how rude customers become the victims of elaborate manoeuvres to give them the worst of what's on offer.

It costs so little to be polite and it pays such big dividends. Moreover it leads to business stability. My company has formed long-term relationships with most of our business partners; this is based on cordial personal ties that both sides have nurtured. Not only does it lead to a certain degree of consistency but it also produces the kind of give and take that makes these relationships so profitable for both sides.

I'm not sure how you put this on a spreadsheet but I do know, for example, that if we unexpectedly run out of something or other it is likely that the supplier will make an extra effort to deliver new supplies regardless of their delivery schedule.

The benefits of good behaviour are more obvious when customers turn into loyal long-term patrons offering repeat business because they feel they are respected and know they will be treated above and beyond the norm.

Just this week I investigated a new bread and pastry supplier, whose products have a good reputation. For some reason there was only a limited range of products available when I went to see them. I asked about other products and was told with a disinterested shrug that they weren't there.

Fair enough but the saleswoman had many options for letting me know what else could be available. I debated for a couple of seconds whether to press the matter but decided not to bother as life is too short to deal with people who can't be bothered. Who knows whether a politer response might have led to developing a new business relationship but I'm not losing any sleep worrying about it.

This is probably the view taken by the board of American Apparel, which must have appreciated Charney's considerable retailing capabilities but finally decided that they could not afford the cost of his rudeness.

It's really very simple: politeness and thoughtfulness works wonders.