All cultures are different. The reason all cultures are different is because people create society. Sociologists call this the social construction of reality. And because all people are different, they create different societies. So, what is common sense and given in one place is not so in another. Based on this point, ethics can differ and they certain do. All you need to do is go from one country to another to see this. Different people prize different things based on where they live.
We can say that this point is also valid on a smaller scale with companies. They have their own culture and ethics. This is why one company is different in feel than another. When we realize this diversity, then we will see where differences emerge. I will add the social theory of Peter Berger as a link.