Do you have to travel for work? When you meet colleagues or potential clients in other countries, the things you do at home that every accepts as the normal might not be okay in another country. In the best case scenario, you might annoy someone; in the worst case, you could lose a huge client, thus costing your company huge amounts of money.
Why risk it? Just learn some key business etiquette differences from the around world, and be better prepared the next time you need to take an international business trip!