A week or so ago Ars technica published a story about some research looking into how chatter on blogs, number of myspace friends or mainstream reviews correlated with sales.
The story was then picked up by other reporting services/aggregators, like Musically, who reported the story as Blog buzz could drive album sales, research suggests. The Musically take on the story suggests causality between blog posts and album sales and goes on to say that the number of MySpace friends a band has also correlates to sales (which the original research does not say).
In the research paper itself the key phrase buried deep is: “…it is natural to ask whether it is reasonable to conclude that increased blog chatter really causes an increase in sales since it does, after all, precede sales. It is not possible to make such a conclusion based on this study.” In fact later on they explicitly caution against assumptions of causality. They go on to talk about various correlated variables. This study only looks at physical sales anyway, and then only Amazon, and then not actual sales but a guess based on Amazon.com sales ranks. Start to see the holes?Among their ideas for future studies includes taking into account the sentiment of blog posts which I think is when it gets interesting.
Sadly, what I think this story really illustrates is how the pressure to find news makes some editors post half baked stories and before you know it everyone in the industry has only read a wrong, short edit concluding things that are half true at best.