If we choose a win-win approach for every situation we face, and get whatever we want by not using others, we can live a better life. The success of others makes us more successful.
Let us take an example of doing business. This principle applies there highly. First of all, try everything you can to see a satisfied customer. Help them in whatever way you can. Even if you can not solve their problems, show them that you care for them. This is called building positive relationship. People love the one who loves and cares for them. This is a win-win approach which results in success for both parties; your customers and your business.
You can take whatever part of your life, work, family, social life... everything. You will be more successful if you only help others to be successful. By success what I mean here is not about financial success only. Rather I mean all rounded success.
There are people who have millions of dollars and do not own happiness, satisfaction, personal character, positive influence on others. I do not consider this as success. Money is not the only thing we need in life.