The most important factor when trying to persuade consumers to purchase or tell their friends about your brand, is your perceived credibility. People need to know that you are authentic, that what you say is true, that you can be trusted. Research study after research study shows that perceived credibility will make or break a marketing/advertising campaign.
Negative comments about your brand increase your credibility. They strip away the corporate sheen. They make you real. People respond better to things that are real.
A brand website, microsite or Facebook page that shows user generated content that is 100% positive doesn’t look real. People have been inundated with push marketing for 20 years. Their default perception is one of skepticism. They can see through the surface layer. People know that no brand is perfect and everyone has room for improvement. So embrace negative comments. Let people say what they want about your brand. It’s better for you in the long run.