Definition of 'Client Base'
A company's primary source of business. A client base consists of the current customers paying for the products, or services, as well as potential customers which have a high likelihood of becoming customers. Businesses rely on this group for most of the business sales, and focus on them for developing new products, or advertising. A client base is usually defined using demographics such as age, location or gender, and can change over time.
Investopedia explains 'Client Base'
Developing, maintaining and expanding its client base is a major concern for any business, since without clients, the business cannot earn revenue. Strategies companies use to increase this base include networking, word-of-mouth marketing and referrals, developing a specialty or area of expertise, staying in touch with existing clients, showing appreciation for clients and consistently meeting or exceeding expectations.
Businesses that primarily provide professional services (like financial planning) tend to use the term "client base", while businesses that primarily provide products tend to use the term "customers". For example a financial planner's client base would consist of all the people who have hired her to manage their money. A CPA's client base would include of all the people and businesses whose tax returns he prepares.