Bottom Line:
The service staff in the US expects to be compensated for the service on top of the price of whatever your buying. Except for the pampering of the well healed they could care less about the quality of the service provided so long as it looks like they are doing their job, and maximizing their income.
In Asia, service is included in the purchase and whatever symbolic "gratuity" that may be offered is appreciated not expected.
In Europe, service comes with an attitude.