Having said that, I think a focus on that particular part of the ecosystem, however novel, isn't really the measure of effectiveness that's most interesting here.
Enough people with the contacts and money to act on their intentions obviously *think* this stuff works to keep people like SCL/CA, AggregateIQ, Palantir and all the others in business.
Psychological warfare /
information operations or whatever it's called this week, has been around a long time. Certainly it's been an explicit field of study in some circles since WW2 and it's been a very active field of study in most of the major military powers in the last few decades. The Blair / Bush propaganda operations that got us into the Iraq war made significant use of it. The 'Colour Revolutions' that took place after the fall of the Soviet Bloc made extensive use of it (and apparently scared the crap out of the Russians in the process). As is the way of things, the claimed effectiveness of this multidisciplinary approach, of which effective market research and profiling is small part, has apparently, on the evidence of this story and others, led to the adoption of many aspects of this body of technique to domestic politics, both here and the US.
It was quite interesting to see this demonstrated so vividly in the C4 sting, where Nix and his colleagues were making it clear that SCL was able to provide, through British and Israeli ex-spook partners, far more than just a bit of psychographic profiling or bot-herding, but could offer a wide range of complementary dirty tricks from the psychological warfare playbook as an integrated package.
Now if we're going to talk about
effectiveness of the body of technique as a whole, I think we have to distinguish between effectiveness in producing
intended effects and in producing
side effects. Using these techniques may be an utter failure in terms of promoting conservative cultural change and/or getting a wanna-be dictator elected or whatever, but may still have extremely noxious side-effects. For example, one side-effect that seems to be at least somewhat correlated with these methods is the promotion of various forms of extreme right political (and even paramilitary) activity.