customer retention
US /ˈkʌstəmər rɪˈtɛnʃən/
UK /ˈkʌstəmər rɪˈtɛnʃən/

1.
the ability of a company or product to retain its customers over some specified period
:
•
Improving customer retention is key to long-term business growth.
•
Our new loyalty program aims to boost customer retention.