Marketing is the discipline that specializes in selling the final products of every company. A company may have the best product with little to no competition on the market and that company will still fail if the actual product is not brought accordingly to the open market.
Marketing strategies are employed by every type of company, big or small, to better place their products on the market and what the consumer buy that product, often times dropping another similar products.
In the competitive market of today, marketing is everything. Worse products have sold in great numbers because a great marketing campaign was put into place, whilst great products have failed because of the reversed reason.