Many people are always on gratitude whenever any person has done great to them. That gratitude sometimes be a bridge towards friendship between person. This kind of action will always be a form of respect and gratefulness towards expressing its own feeling.
There is no denying that any people who received something good in the past will surely repay with gratitude towards the person who has done great things to him. It may also be a form of communication wherein you express your thankfulness at the same time respect towards a person.