Word of mouth advertising – good or detrimental?

I am a member of the Linked-in Business-Intelligence group and find it most useful. I particularly like  Jared Matthew Kessler’s blog entries, they are always thought-provoking and to the point. His recent blog post

 As someone who is involved in “Business Intelligence,” how do you get someone to sing about you? Some unconventional insight

is a terrific example of the powerful impact word of mouth – or in this case  – exposure on the net  can have on influencing customers- potential and actual.  (Have a look at the link, it’s brilliant!)
In this case United Airways very soon learned how powerful this sort of unwanted advertising is – their share value dropped and they have finally admitted that they need to pay attention to their customer service – but do we Mikronetters ever hear if there is adverse mouth to mouth comments about our services?