That word of mouth is a crucial part of any marketing effort is pretty well established, with well known idioms around the number of people who share bad experiences dwarfing those who relay happy ones, an example of how such viral messaging has entered the mainstream.

This has certainly perpetuated in the online world, with numerous studies highlighting the persuasive power of user reviews.  A recent study has set out to explore this world in more depth, and especially understand what may cause peaks and troughs in the reviews users give.

“Previous investigation into online communications had focused on product reviews, but it was clear that far more information was needed,” the authors say. “The current study hypothesized that additional platforms such as blogs, forums, and social networking sites would give a richer picture of the many factors determining how electronic word-of-mouth affects sales.”

The paper found that reviews are far from equal, and far from equally beneficial in all circumstances to all products.  That may have been expected (as if they could ever be anything else), but the findings still provide some interesting nuggets of insight.

For instance, online reviews were found to be much more beneficial for durable products than their nondurable peers.

Reviews were equally powerful for products in fast moving technology.  In this kind of scenario, word of mouth was much more reliable and credible than advertising.

Interestingly, specialist review sites were often more influential than reviews left on general sites.  Whether this is unduly influenced by the likes of TripAdvisor is hard to say however.

A final interesting nugget was around the username under which the review was left.  Perhaps not surprisingly, sites that encouraged reviewers to do so under their own name were seen as more reliable and trustworthy than those whereby reviewers were largely anonymous.

“The findings have clear implications for durable or high-growth product sales, which may benefit greatly from electronic word-of-mouth communications. Importantly, the medium is indeed the message. The type of platform carrying the information has a large impact on its effectiveness,” the authors conclude.