In it he cites the recent NYTimes article (Bad Publicity is a Good Thing [nytimes.com]) about a merchant who bragged that his negative reviews helped boost his site to the top of the SERPs, and a Google blog post [googleblog.blogspot.com] in response where Google states they tweaked their algo so that negative reviews no longer help rank a site. Danny calls this tweak, Sentiment Analysis. The article does not say that linkless citations are driving high rankings, only that it is likely that linkless citations may be a factor.
It seems likely that Google is now using these reviews as part of its ranking algorithm... That doesn't mean reviews necessarily override all other ranking signals but rather that they are yet another factor among many to be considered.
Reviews have been a component of the local search ranking algorithm, this was a hot topic of informal conversation at the recent Vegas PubCon. Some suggested hiring link monkeys to visit all sites that are cited in Google local and having them drop reviews and site mentions.
Linkless Citations Beyond Merchant SERPs Let's expand this discussion to beyond merchant reviews. After all, if this works for merchants, then maybe it would work in the general SERPs. For instance, some people claim that no-followed links help a site rank better. Could it be it's the citation itself and not the no-followed link that could be contributing to ranking a site? It is a citation, right? Citations are the foundation of PageRank.
Is it far fetched to assume the possibility that Google has moved or may be moving toward including other forms of linkless citations as part of the ranking algorithm?
And if so, what other forms of linkless citations could they be using?
Is it time to at least provisionally redefine what constitutes a citation?