I think industry has a lot to do with the answer to this. I am in the Tech Industry so often see people jumping from job to job every few years. However, there are definitely people within the industry who are long-timers as well. It also is somewhat generational as well. I am in my 50s and find that people from my age demographic often stay with a company for a longer period of time. That being said, I do not hold the length of time someone has worked at a company against them. Unless, that is, they are not willing to take the time to learn about the new company they are at. If someone is obviously just interested in fulfilling their individual needs and not the company needs, then they will not be successful as a short-timer or a long-timer. I must admit that I feel there is a great advantage to long-timers simply because they can know the unwritten rules of a company, or know the unwritten ways to get things done, or know who to go to when you have a certain type of question.