The Reason I find SEO fascinating is there is no easy rule book to find and follow. Side note: I believe If you serve the user right, you will rank higher over time. Back to my main point, I googled for a book and noticed Amazon.in ranked #1 & #2.
The same book on #1 & #2
I knew this sometimes happened when the links linked to different formats of the book, but today that was not the case, both linked to the same book, to the extent, both say I purchased the book.
The Two pages
Here are the links
So I investigated further. It turns out; both have the same canonical URL too
A quick check with Small SEO Tools on the links shows that the content is the same, which you can eyeball frankly
Content is the same
So, it looked like Amazon is sending google bots to different pages, and humans to different pages. To confirm, I just opened the cached versions from Google.
So google bot is indeed going to different pages. Next, I checked the Canonical links to the page.
Google Bots view of the pages
Different Canonical links.
Google Bot Canonical Links
Folks at Amazon is defiantly on the top of the SEO game :). I close with the same line as I started, there is no easy rule book to find and follow for SEO; you need to experiment and find your own rules.