Interesting post - I think we often forget the power of online in selling physical product; we so often think in terms of the reality or virtuality of the product itself (CD or download) and whether we consume it through a traditional live shop or a personal electronic device, but forget that people who still prefer a tangible copy of their recorded music will now increasingly just order it up from their armchairs as they would a digital item.
Since CD singles fell off the cliff at the turn of the decade, I don't buy many CDs - I never did purchase that many albums, on any format - but the few that I have felt compelled to buy have been split between online and physical retailers. Contemporary easy-to-obtain stuff I'll usually trot along to HMV (we somehow still have a resurrected branch in the town where I work despite the original one having closed!), while more unusual items I'd go via Amazon. Costs aren't that important as I buy so little now, so if I don't always bother shopping around to find the best bargain it's not a big deal.
I think it's important that some real-life High Street record shops still exist though, albeit that inevitably it will be in a much-diminished number and with uneven geographical coverage. There's sometimes no substitute for flicking-through CDs, vinyl - possibly once again even cassettes - in a shop to 'get the feel' of the actual product, especially if it was originally issued in a physical format. To those of us for whom that experience was ever the norm, I think it's comforting to know it can still be done, however few places there may be, and however seldom we actually ever go and do it. Trouble is, nostalgia alone won't keep the stores alive; people have to buy - which is why we should be so grateful to those supporting the vinyl mini-revolution, as although many will use Amazon et al, they're sufficiently-engaged with the 'cult' of physical product that a goodly number will always prefer to shop for it in the time-honoured traditional manner: in a record store.