Loyalty is devotion and faithfulness to a cause, person or country. To be success in life you need to be loyal. If you are not loyal to your team, you can get by for a while but eventually you will need to rely on their loyalty to you, and it just won't be there.
Loyalty is one of the foundation stones for a balanced success. If the people working in a firm are not loyal, I don't think the firm will last. You need to be loyal to your superiors and to yourself. It is a very important virtue; don't sell your loyalty for any reason. The spirit of loyalty gives a sense of security to the firm.