What is CI Branding? Does it make impact on business.

I think you mean Co-branding not CI branding

Co-branding is the practice of using multiple brand  names together on a single product or service. The term can also refer to the display of multiple brand names or corporate logo s on a single Web site, so that people who visit the site see it as a joint enterprise. When effectively done, co-branding provides a way for companies to combine forces so that their marketing efforts work in synergy.

For Instance : On the Internet, co-branding can provide benefits to the involved businesses by enhancing product or service exposure to consumers, marketing new products and services, and making consumers or clients aware of the core competencies of each enterprise. Co-branding can also be used to target specific markets with advertising by means of banner ads, logos, or links in descriptive text, maximizing the likelihood that potential buyers will learn of the existence of a particular company, brand, product, or service.

Yes, it has deep impact on business.  

In addition to Mr. Mohammed Ashraf answer which I agree with, I guess you mean Corporate Identity;right?

A corporate identity is the manner which a corporation, firm or business presents themselves to the public, such as customers and investors as well as employees. It is typically visually manifested by way of branding and the use of trademarks.

So technically it is the identity of the company, and definitely it impacts business !