What is better for sales, organic or paid marketing? Explain why?

Well, from my opinion the paid marketing is required at the beginning since there will be almost no one who knows about your product, but at some time the organic will be the best once the word of mouth gets to be enough to spread to the rest of cutomers, in that case all customers will mostly shares same interests when sperading the word, and hence the better effective marketing it will  be.