"When I tip (outside the US) its done so as a genuine expression of gratitude for good service. It's my way of encouraging and rewarding good service. If its done under compulsion than its no longer a tip, it's a charge and good service is relegated as less meaningful."
That's interesting.
When in Europe I've found it pretty common to see a "tip" section in the bill, where the tip is already added on to the bill by the management and counted in to total you have to pay.
That's rare in the US, where at most one sees a "suggested amount", and usually tipping is completely optional.