[panarky]

Advertisements for consumer products are effective precisely because they cause psychological and behavioral changes in consumers.

Companies rigorously test and refine ads to manipulate emotions and behavior on a scale two or three orders of magnitude greater than Facebook's experiment.

Is Facebook's experiment different because they published the results in an academic journal?

[hyperpape]

I tend to think this experiment is a good example of where informed consent is a limited model. Nonetheless, academic researchers are committed to not do this kind of thing, and breaking your commitments isn't awesome.