Stephen linked me to The Ecommerce Scam today.
As I see it the problem boils down to folks not having specific & up-to-date domain knowledge. Whilst its fun in some cases to read a bunch of review sites & blogs and learn about all of the factors relevant to your purchase of a camera or a new laptop, its not practical nor necessarily enjoyable to do that for every purchase you'll ever make.
Hunch could help to solve this problem as it allows users to essentially build expert systems. Users can build decision trees that guide other users through a series of questions before arriving at some conclusion. e.g. if you're buying a camera it might ask you what your budget is, how important size & weight are to you, etc.
However there are two problems I see with using Hunch for this purpose. The first is trust - I don't know if the users creating Q&A are actually knowledgeable in the specific fields. Obviously this makes their recommendations questionable. Secondly even if they are experts I don't know whether they're in a position to keep their knowledge & recommendations up to date. For something like a camera or a laptop this is pretty important given how frequently new products appear.
Both issues are solvable - users already go to specific review sites like Digital Photography Review. They trust DPReview know how to evaluate camera performance, and as they're constantly posting reviews they know that the folks behind it are up to date.
What's missing is a simple way to digest all of their reviews into purchasing advice. DPReview has a buying guide but it is essentially a feature search which isn't all that useful if you're not already knowledgeable about how the features affect usage, nor does it factor in their own reviews of actual performance.
To give another example a question I am regularly asked is "What ISP should I use?". I'll usually recommend a few ISP plans based on my understanding of how many GBs/month they're likely to use, what they intend to use it for, and available service in their location. For someone who's big on gaming and/or cares a lot about speed & performance I'm going to recommend premium ISPs such as Internode or iiNet, whereas someone who doesn't care so much about their pings & speed or reliability but cares more about value for money I would recommend to Exetel or TPG.
This stems from my understanding of how these ISPs run their networks through direct experience and the experiences of technical friends that I trust, as well as knowing people who work in said companies. There are aspects of the service beyond price such as redundancy & performance that are not immediately obvious to the average consumer but with just a few questions & knowledge of the industry one can reduce over 200 ISPs & several thousand plans to just a few options worth considering.
It would be awesome if someone were to offer a Hunch like service as a white label / embeddable service. Sites like DPReview could use it to build a friendlier filtering mechanism which asks the appropriate questions, then whittles the myriad of brand & model choices down to just a handful of realistic options, factoring in their review data.