Someone said “Social Media is the future of all businesses”. Everything you own today that you want people to know or you want to sell it to people can be very easily conveyed using Social Media-The Biggest Platform for business today.
There are various ways to do viral marketing. Some are discussed here. There are many reasons why people share like Emotions, Humorous, Makes them think, Uncommon, etc. One should have a great deal of idea on the niche they have. Their demographic, the target audience is what is of the most importance.