Perhaps we've all succumbed to regarding Amazon as the only choice, given the behemoth it has become, selling everything from vitamin supplements to sunglasses. But there are alternatives, not least if you're buying books. I can recommend Wordery; a huge selection of books at discounted prices (and cashback if you go via its Quidco link), professionally run, and free delivery worldwide (no minimum order necessary, unlike Amazon). Have also ordered from A Great Read; a smaller selection of books but very good discounts, free UK delivery on all orders and excellent customer service. For example, Anna Jones's A Modern Way to Cook is £17 on Amazon but £12 on A Great Read.
And unless I'm buying books as gifts, I can find many of the titles I want to read at my local library; otherwise reservations are just 50p a book. The only exception to that is if they have to reserve a book from a library outside the county, in which case it will cost a little more. My library managed to track down an out-of-print book, which I needed for research, at a college in Winchester. It cost £3 to borrow via an inter-library loan - and second-hand copies were listed on you-know-where starting at £75!
The one stumbling block, I thought, might be e-books for my Kindle but there are alternatives. Just ask Google the question!
For non-book purchases, I just do best price searches and now find that Amazon is rarely the most cost-effective option. So, even without the word 'boycott' passing one's lips, if you don't mind spending just a few extra minutes online, checking for best prices, you'll probably find that Amazon doesn't necessarily come out tops.
Anyway, do hope this might be useful to someone!
(As for Clarkson, nothing would persuade me to watch anything in which he appears, wherever he crops up . . .)