“Li” in China not only refers to not only gifts, but more often than not, courtesy and modesty towards people. Politeness is extremely important in contacts among Chinese people. It helps you approach the other side and establish a good relationship.
Politeness or rudeness is a key factor behind success or failure in China. When you succeed in making the other side feel that you respect him, you will find your next meeting much easier. There are many instances of seemingly difficult tasks that have become easier with politeness.
Inexperienced young people may sometimes think too highly of themselves and are likely to attract resentment from people around them by thinking pompously as if there were nobody around. This kind of rudeness is fact is a hidden obstacle to one’s career development. With politeness, you can go everywhere.
Also, people sometimes translate that “li” into “reason”, as “reason” and “politeness” share the same pronunciation in Chinese. So, if you have acceptable reason, you can go everywhere as you like.