Amazon killed off their 20% off preorder discount on games awhile back, and it made some major waves with consumers. Many were upset to see the discount go, and wondered why it was yanked. Now we're hearing that Nintendo may have been a major factor in the decision.
As you well know, Nintendo and Amazon have had quite a tumultuous relationship, and those flames may have only been fanned by Amazon's preorder discount. Nintendo was supposedly so against the idea that they yanked their software lineup from the retailer, and didn't give them stock until 2 weeks after launch. Nintendo let Amazon know they weren't okay with the 20% discount, and showed them as much by withholding stock. It was this move by Nintendo that inspired other publishers, who ended up putting the pressure on Amazon as well.
Obviously Nintendo nor Amazon is going to comment on this matter, so we'll just have to take the inside information for now.