Why is retail sales is more important that corporate sales . or which one is better in terms of sales and from the profit prospective .?

the free or retail sale is done directly with the consumer so it will directly create the image of the product and the brand and ensures the maximum desired building (cash)against the sale to the companies it is also a good technique but with delayed harms (differences of system of payments of the companies)

Retail sales create a brand image of your products or services  in the eyes of buyers or consumers. Companies or industries used this strategy to grab the maximum market share which ultimately resulted as a desired profit. 

corporate sales also good but not sure for earning of  targeted profit.