Advantage of staying in the same job for the same company
Practice makes perfect. After working at a certain position long enough， a person will become very familiar with the work procedures and will be much more experienced， skillful and efficient than new comers in dealing with various tasks at this position.
Loyal employees are more likely to be promoted. If a person stays in a company longer than others， it usually means this person has made more contributions and is more loyal to the company and thus will have better chance of being promoted.
Staying in the same job increases a person's self-value. If someone keeps on learning the latest knowledge and skills at a certain position in a certain field， this person will eventually become an expert or a professional or at least a highly skillful worker in this field， earning much more than other fresh-hands.
Disadvantage of staying in the same job for the same company = advantage of changing jobs
Some companies are not worth a person's whole career life. There are some companies which lag far behind their competitors in a certain industry. They offer much less reward for their employees and they do not have a fair promotion system or a reasonable welfare system. Some can barely survive in today’s competitive society. Therefore both in terms of remuneration as well as career prospect， working long for them is not wise.
It is not easy to find an ideal job the first time you look for it， especially for fresh university graduates. Sometimes it is only by trying several jobs can a person eventually know what he or she likes doing most or can do best. Sticking to the wrong type of work makes it impossible for a person to enjoy working.
Some work is so boring that if someone keeps doing it for too long， he or she will feel dull and will become less interested and careful in doing that work.
