At its core, customer relationship management (CRM) is all of the activities, strategies and technologies that companies use to manage their interactions with their current and potential customers. A saying frequently heard and said in many businesses is "customer is king."
CRM helps businesses build a relationship with their customers that, in turn, creates loyalty and customer retention. Since customer loyalty and revenue are both qualities that affect a company's revenue, CRM is a management strategy that results in increased profits for a business. At its core, a CRM tool creates a simple user interface for a collection of data that helps businesses recognize and communicate with customers in a scalable way.
Leslie Ye, editor at Hubspot’s Sales Blog, describes a CRM in the following way: “Beyond contact info, CRMs log reps’ touchpoints with their prospects, including emails, phone calls, voicemails, and in-person meetings. Some CRMs offer the ability to track deal stages and reasons for closed-lost and closed-won deals.”

According to Gartner, CRM software totaled $26.3 billion in 2015 and predicts that that figure will continue to rise through 2018.
At its core, customer relationship management is simple. However, it can be implemented in a huge array of methods: websites, social media, telephone calls, chat, mail, email and various marketing materials can all be integrated into a CRM solution. Due to CRM's diversity, it doesn't only benefit larger businesses -- using and maintaining a CRM tool is the basis for a scalable sales and marketing system. Any company will benefit from maintaining a record of which conversations, purchases and marketing material can be associated with leads and customers