Such a temporary argument, especially when you consider Amazon has "increasing selection" as a core tenet[1] of how they grow any business they've created over the last 20 years.

[1]: http://g-ecx.images-amazon.com/images/G/02/uk-careers/jfsfis...

And 400 of Amazon's 1 million songs are by Johnny Cash.

http://www.beyond-black-friday.com/2014/06/12/amazon-announc...

Sure, but Prime Music is also only a few weeks old