Customer Service means “helping, guiding, assisting and caring” to customers during “concerning, analyzing, purchasing and after purchasing”. In a sense, all caring activities to customers in sales process engineering are called customer service.

Thus customers maintains an active role in an organization's ability to generate revenue and income, good organizations spend more money on customer service to create value than the average organizations. 

Although a formulated or structured customer service was maintained from pro-1870 but unconsciously it was started during the time of “barter system”. Because when one person went to another to exchange his or her goods fast person had to say the features about his or her goods to second person. This providing information is one kind of customer service.

However in Bangladesh, structured customer service was started by the development of telecommunication sector. Earlier it was not maintain by giving as importance as today is giving. In earlier 2005 organizations spent less than 1% of their income on customer service but now they are spending more than 13% of their income.