Business Small Business. Inflation Definition Inflation is the rate at which the general level of prices for goods and services is rising and, consequently, the purchasing power of currency is falling. In simple terms, it is measured by calculating total revenues against marketing investment. From Wikipedia, the free encyclopedia. For ROMI to be effective, it is important for the campaign to have some measured metrics. To be clear, marketing is an essential part of most businesses and can pay many times over what it costs. Description: There are several reasons for a company to go for rebranding.