Why does my VPN browser open the India-linked Amazon website instead of the local one?

I am having few question with Amazon affiliate links which I am trying to understand. 

The question is: 

In this code, what is gg3. https://www.amazon.es/s?k=Hot+products+on+Amazon&linkCode=gg3&tag=latestfotocom-20

although I clicked on a button which is linked with a url:  https://www.amazon.com/s?k=Hot+products+on+Amazon&tag=latestfotocom-20

In last one url link, you donot find "amazon.es/" and "&linkCode=gg3" because I have an affiliate account for USA linked Amazon affiliate program. 

But I am based in Spain. 

Since I am based in Spain, so I can understand that "amazon.es/" is appearing because it opened a Spain based store of Amazon but I did not understand why "&linkCode=gg3" is appearing. 

Then I used VPN browser and this way I won´t be identified that I am based in Spain. 

But there was a surprise. 

I opened the HiChicas.com in VPN browser and the website opened perfectly.  

Here, all these names of continents (North America, South America, Europe, India, Asia, Africa, and Australia) are linked with Amazon affiliate url. 

Now, when I clicked on "North America", I found that Amazon website did not open as you can see in following screenshot image. 

Then I clicked on "South America", "Europe", they also did not open. 

Next, I clicked on "India", it opened perfectly in VPN browser as you can find in following screenshot image. 

I surprised why it is happening. 

Next I clicked on "Asia", "Africa", and "Australia" and they also did not open. 

Now I was having question: 

Why did only India linked Amazon website or store open in Spain or Europe on VPN browser. 

Yes, I was accessing VPN browser from Spain. 

I am curious to know about "&linkCode=gg3" and why VPN did not open other Amazon stores. 

If you have any answer, you can share in comment section.