what'is public realation needed??

I think public relation (PR) is needed to:

1 Promote the company in good way

2 "Defend" the company in case the company has any negative events

Below are from Wiki, you might find helpful

http://en.wikipedia.org/wiki/Public_Relations
Examples/users of public relations include:
Corporations using marketing public relations (MPR) to convey information about the products they manufacture or services they provide to potential customers in order to support their direct sales efforts. Typically, they support sales in the short to long term, establishing and burnishing the corporation's branding for a strong, ongoing market. Corporations using public relations as a vehicle to reach legislators and other politicians, in seeking favorable tax, regulatory, and other treatment. Moreover, they may use public relations to portray themselves as enlightened employers, in support of human-resources recruiting programs. Non-profit organizations, including schools and universities, hospitals, and human and social service agencies: such organizations may make use of public relations in support of awareness programs, fund-raising programs, staff recruiting, and to increase patronage of their services. Politicians aiming to attract votes and/or raise money. When such campaigns are successful at the ballot box, this helps in promoting and defending their service in office, with an eye to the next election or, at a career’s end, to their legacy.