Where Best Buy failed..
In my opinion..
Best Buy failed for a combination of reasons.
1) Little or no advertising. They assumed (wrongly) that the bulk of the UK population would know them from their US roots..
2) Where they did advertise, they advertised large selections of goods at low prices. What I got whenever I went into the BB on Purley Way in Croydon is an (admittedly) large selection of goods at high prices. John Lewis isn't particularly cheap, but they are just up the road from that store and considerably cheaper for electronic goods. They also have the advantage that they have established a good reputation for after sales service.
What they should have done is what Argos apparently did when they were first launched. They should have had incredibly low prices, and blitzed the country with advertising telling us how cheap they are but how they somehow maintain good service (I know that Argos isn't really a good example of good service).
Then they can do what Argos also did, and having hooked their target customers, raise the prices gradually.
Oh, and launching when we are out of recession might have been a good idea as well.