Volume is defined as the number of items sold, or the number of recruits in the networking business. There are various definitions of volume depending on the type of business operation a company has. Some refer to volume as the number of shares a company has, when the company is involved in stocks. Others define volume as the number of markets targeted for a specific product. The volume, whether it pertains to products, people or investments, is necessary to measure the potential success of the business. In network marketing, the volume of recruits is essential to keep the commissions high. This includes finding people to join in the downline.