People think marketing is a mechanism to create money. This may be the by product of a successful marketing endeavor but its more productive to think of marketing another way.
As the way we connect business ideas to the human mind.
Peoples minds are crowed with thousands of ideas and brands - all layered with emotions and stories - with some of them actually being true and most of them being a lie that they just tell themselves.
Marketing is the very mechanism that helps ideas spread.
It is the process of how we take an idea, put it into someones mind and change them as a result. Change them from someone who likes Pepsi to who likes a Coke. But most of the time, as you will realize - is that these ideas don't change them but rather is there to reinforce and poke at the ideas that they already wanted to believe.
Marketing is the act of engaging with the human mind. Working with it to create memories, tension and change.