Is it necessary to build strong customer relationship so that you can generate revenue for the company?

Yes sure, Some of customers love to feel that they have a friendship with the company's employees, Some of them better to not have this kind of relation with, They will use it badly.
In most of cases having this relation is very important to revenue the business.

In sales this is called building rapport.
and yes building rapport is one of the most fundamental sales techniques.
In sales, rapport is used to build relationships with others quickly and to gain their trust and confidence.
It is a very powerful tool that veteran salespeople naturally employ, which allows them to close more deals with less effort.

VALUE YOUR CUSTOMER RELATIONSHIPS AND GET GUARANTEED INCREASE IN REVENUE FIGURES FOR LONG TERM SALES - Customers are assetes to the company, without them how will the company survive? If you maintain a good relationship with them, they will come and bring fresh blood not only for the brand but for you as their consultant/sales/ customer service agent etc...
- Initiating and maintaining profitable long term customer relationships is a fundamental requirement for generating valuable revenue for any profit working organization.
They will bring new customers to you if they are satisfied with your services, they will refer you to friends, familly, co-workers etc...you get customers out of your current customers.
- Building on this notion, the staff/sales/customer service agent should emphasizes the importance of initiating long-term relationships, understanding how customer relationships develop over time is therefore of central interest to the company itself.
- If the above is not implemented on the customers, you will have the risk of contract termination between both parties, or customer cross buying in the future and even negative word of mouth marketing from them .
- That's why news letters CRM software are very important to maintain good relationships with them, (ie: birthdays, anniversaries, follow ups, to show them how much you care for them, and need them.
Or even just a simple phone call to ask them how are they doing etc...this can maybe bring out another sale, or even bring a new customer from their end.
Be close(not to close as well) to your customers, have a good relationship with them, or you might loose them to competitors within your company (this specially applies for sales) or against a competitor brand.

 yes its very important and necessery  to build ea relationschip with your cosytemers that mak a good repute to your company.