I just got back from Europe and there is not tipping over there... Cabs, Restaraunts, Hotel Clerks, etc...
It all depends on the wage structure and how tipping should be conducted. In Eurpope they make money off of quality and length of stay per table; wheras, the U.S. is purely volume driven.
For example... In Barcelona, Brussels, and London the normal dinner time is 8 - 9 ish and usually is a 2 - 3 hour long even when going out. Usually people will have 1-2 beers with apps, 1-2 glasses of win with dinner. The courses are the apps (1-2), the main, dessert, and an after dinner coffee. Many people even end dinner with spirits (like a Bailey's or something). The bill will usually come to 50 - 75 Euros (times by 1.3 for USD equiv) per person and their "Tip" is included in the price of the meal.
I think the wage structure is similar in Canada where the service folks are paid occordingly to the pricing structure of the meals. The items on the menu are priced at a profit thus the servers are paid accordingly.
In the US many of the items are priced at a loss; while drinks, desserts, and apps make up for it. The service folks are paid less then Minimum wage with the expectation that tips should more than offset the difference. So the incentives are different for different countries.
BTW I will not tip the Chinese food people or Subway type places for simply making the item. There has to be a level of customer service involved to deserve a tip.