So if I buy from Waterstones or W H Smith then I know they are paying more taxes, that's a good reason to buy from them. When it comes to real books some companies (such as Wordery) pay taxes and undercut Amazon so win win.
Actually you don't know for certain, I said when you have physical shops its harder to play the system but that doesn't mean it can't and isn't done. If the tax issue is important to you then its something you need to look into each company carefully.
For example some of these highstreet stores have their online operations run separately with like Amazon as much of it as possible operated abroad so they can skip tax.
There are so many ways of legally 'hiding' income to reduce tax liability that they all use, its just Amazon/Starbucks/Vodafone/etc method was perhaps more obvious and when the media was looking for story it was an easy one to understand to get people in uproar.
It should also be noted that the high street stores arent adverse to using the the governments 'back to work schemes' for unskilled jobs so there are no wages (or tax/NI) to pay and they also get payment for letting these people work for them for free. This is just as bad really, Tescos who are about to launch an ebook store via their Blinkbox service are one of the worse abusers of this
They really all are as 'guilty' as each other, not that they are really guilty of anything but doing what they are supposed to do and pay the least tax they are legally entitled to pay while providing their shareholders with the bext return