False Marketing vs Company's Credibility; how much a company's credibility is affected by a false marketing campaign? (end-user wise)

in todays social media presence  negative feedback can destroy a company's reputation in a day.

Company's credibility is definitely gets damaged because of false marketing campaign.
you can always have a fresh line up of consumer with the help of false marketing campaign but you would never be successful in making a loyal base of consumer for your product or services.
if you don't have a loyal base of consumer as a company you can't be successful if you move forward for brand extension i.e product line growth vertically or horizontally.
Nokia Lumia 920 'Fake' Ad Affect its Sales and Credibility In Sep 2012 Nokia released photos that compared the new device's camera capabilities that of other handsets.
However, the images were proved to be illegitimate and fake.
Nokia apologized to the public admitting that they did not use the smartphone in taking the photos so that they can save their company image.
In one of the videos, , a reflection is clearly visible that shows a camera crew with lighting rig moving parallel to the video's subject.
The camera crew is not using a Lumia 920 to shoot the video but a dedicated video camera.
The faked video was pointed out by The Verge.
Nokia has been tripping over its tongue ever since.
First the company said the video was meant to demonstrate the benefits of OIS in general, not specifically the Lumia 920.
Too bad the video was pitched as a sample taken from the 920.
Then it back-peddled and issued a broader apology: "In an effort to demonstrate the benefits of optical image stabilization, we produced a video that simulates what we will be able to deliver with OIS.
...we should have posted a disclaimer stating this was a representation of OIS only.
This was not shot with a Lumia 920.
At least, not yet.
We apologize for the confusion we created." Many reports claimed that it could cause damage to Nokia's credibility as well as to the projected sales of the new Nokia Lumia 920.

Agreed with Mr Faizan's answer. 

But not all of the time false marketing would affect a companies credibility. Sometimes, marketing experts uses this oppurtunity to gain more audience or to market their product. In a social media for example, a company is getting a negative reactions with the product because a false marketing campaign not knowingly that its a part of their marketing strategy to catch more viewers or listeners to promote another new marketing campaign for a new product line.

Very true Amer but what about the enduser, his safety and his satisfaction...if a company's reputation is destroyed because of social media should we blame the media or the company?

True false marketing destroys the credibility of any company.