do u know what does PR mean?  

It means public relations.

PR means Public Relations. Many people mistake pubic relations for advertising, but the two are not the same. In advertising you advertise a product in print, tv, or radio. Public Relations is more like the means of making a company known or popular. In PR the term "There is no such thing as bad publicity" appears very often because as long as people talk and are interested in a company, their reputation will increase. Ads for PR look more like opinions of things. For example there is this PR ad from SHELL. Their print ad is a green pasture with a hay-car on it and it says that this is and environment friendly car. In this case, SHell is promoting environmentalism which shows that SHELLS interests are not only in the polluting gasoline and oil, but also in global warming, and with this public dispaly through PR, the general consumer starts to favor SHELL more and will probably get their gasoline only at SHELL. Its a bit complicated. but If you have more questions just ask, I have studied this for 4 years haha ^^