A common mistake that businesses make is to focus and invest more in sales growth by attracting new customers than maintaining existing ones and building a long-term meaningful relationship with them. Yet the latter is valuable for the development of the operation for the following reasons:
80% of future business profits come from just 20% of their existing customers. Should the retention rate of existing clients increase by 5%, the company’s profit can be increased from 25% to 95%.

Existing customers spend 33% more money than new customers. It is 14 times more likely to buy a brand, and 50% more likely to try new products of the same brand in relation to new customers.
The cost of attracting new customers is seven times the cost of keeping existing ones.
73% of the existing customers are more likely to recommend the brand to others. Indeed, the positive testimonies via word-of-mouth or over social media is much more likely to affect other consumers than the promotional activities of a brand.
The existing customers will defend the brand that consistently choose in cases of new competitors or defamation and are more willing to pay higher prices for it in relation to new customers.

 
 
Source: David Aaker and Andrew Marcum (2017), Eric Siu (2016), Ayodeji Onibalusi (2016), Jana Barrett (2016), Michelle Markelz (2016), Jerry Jao (2015), www.retentionscience.com, www.invespcro.com