Collocations for customer - noun

big, favoured/favored (esp. BrE), favourite/favorite (esp. AmE), good, important, key, large, major
They are one of our biggest customers.
They organized an evening's entertainment for key customers.

long-standing, long-time, loyal, valued
regular
current, existing, old
repeat (AmE)
new
potential, prospective, would-be
There are a large number of potential customers for the new product.

paying
dissatisfied, unhappy
angry, irate
happy, satisfied
We like to think that we have satisfied customers.

domestic
internal
external, outside
foreign, international, overseas
personal, private
business, commercial, corporate, industrial, retail

have
deal with, help, serve, service (AmE)
attract, draw, entice, get, lure
It's a special offer to attract new customers.

lose
We can't afford to lose any more customers.

keep, retain
satisfy

care, relations, relationship (AmE), service, support
If you have a complaint, contact the customer care unit.
Part of good customer relations is knowing how to deal with complaints.

account, order
agreement
The terms of the guarantee will be set out in the customer agreement.

demand
This cheaper model was produced in response to customer demand.

demands, needs, requirements, specifications
feedback, reaction
The questionnaire is to test customer reaction to the new store design.

dissatisfaction, satisfaction
They carried out a customer satisfaction survey.

loyalty
complaints, enquiries (BrE), questions (AmE), requests
hotline
survey
data, information, profile, records
base, list
They are hoping that TV advertising will increase their customer base.