The idiom for this week is often used to talk about customer service. It is to “go the extra mile”, and it is used to talk about a person who gives someone service that goes beyond expectations. For example:
I really like the service at this store. They really go the extra mile for their customers.
Brenda is the best salesperson on our staff because she always goes the extra mile when serving her customers.
ABC Company is a very important client for us, so I want you to go the extra mile for them.
John was the most popular teacher at this school because he always went the extra mile for his students.
This expression always uses the word “mile” even in countries that use the metric system. Therefore, we NEVER say to go the extra kilometer.