It is widely used as a gift and most of the people like to receive or send flowers on different occasion and mark the event with a sense of romance and individuality.
Flowers has the power to alter any one's mood and bring the sunshine of happiness in the darkest of dawn then why not treat someone special to you on their birthday, anniversary, engagement, baby birth or any other day cheerfully with flowers.
At times it's really impossible to payback or reward the person in a why he do for you. The only option left is to show your sincere thanks. The way you say thank you matter a lot.