Earlier quoted context omitted.
> Why do you think that Amazon is concerned that a database is enough to threaten their business? Didn't the GP already answer the question you asked of them? >> It was a purely defensive move to prevent anyone else from acquiring or partnering with Goodreads, because their database of books and reviews could be used to instantly start competing with Amazon's book business. Amazon snuffed out that threat of competiti…
On Goodreads, the Buy button allows you to buy from: - Amazon - Audible - Barnes & Noble - AbeBooks - Walmart - Libraries
Interestingly, 3/6 of the places you list are owned by Amazon.
And all those options are hidden behind a menu. I checked a few books on that site, the button itself is always either "Buy on Kindle" or "Buy on Amazon" (if Kindle isn't available).