“Sentiment is the poetry of the imagination”. Google has now started using Sentiment Analysis to rank websites on its search engine. This would slightly affect the rankings of all the existing websites. SEO is now going to add a new criteria into its text-book.
Sentiment Analysis is exceptionally challenging as computers are very poor at understanding irony, subtext, implicit context and all kinds of other linguistic constructs that a human reader easily comprehends.
From the Google Blog:
The sentiment analysis identifies negative remarks and turn negative comments into negative votes. Using sentiment analysis in search rank is tricky however, because it would also pull down sites about unpopular politicians and controversial issues.
This led to a state of dubiety in choosing a solution for the “Bad to customers = Good for PageRank” problem. Instead of using either of those two solutions to account for cases like the one described in the New York Times article, Google instead compiled a list of hundreds of merchants that provided “bad user experience” and algorithmically forced them lower.
Further, Google admits that it may not be a flawless method in ranking algorithms. But for now customers using Google search for shopping, and status of Google in public, got just a bit safer.