Answer:
Increasingly customers are relying more on third parties to make their buying decisions (rather than through traditional paid for communications such as advertising). These third parties or advocates can be friends or family, experts such as doctors, social groups or journalists.
Brand advocacy is the recommendation of a brand by one of these influencer groups. Since Bain and associates identified that brands that the highest levels of brand advocacy, outgrow their competitive set by X2.5 times, businesses are increasingly looking at how they can maximise this advocacy.
A good Blog that talks about some of the techniques companies are using to build brand advocacy is www.wordofmoss.com
Another great resource for learning about Brand Advocacy is www.zuberance.com