I think in the UK the culture is different. We (usually) only tip if the service given is 'beyond duty'. In other words great customer care given.
In the U.S it seems to be different. Maybe you guys can help us Brits understand why you have to basically tip everyone.. Is it usually because the wages are too low? I must admit I don't like the idea of someone expecting you to give them extra money when you have already paid for the product, an example would be: If you went for a meal, you pay for the product offered - the product is the whole experience, that experience includes service!