Amazon works very well for self-published authors. A lot of them went the traditional route and went self-published and made a crap-ton more money as self-published as they ever did, plus they retain the ownership of their own works. http://www.hughhowey.com/
That's Amazon's whole point. They have the data that shows that $9.99 is pretty much the sweet spot for "major label" authors, and 5.99-7.99 for all other authors. Publishers would make a lot more money if they priced the ebook at $9.99, but they have to protect their print sales so they generally price the ebook at $14.99 so that the $12.99 paperback looks attractive.
The other forgotten point in this discussion is that traditional publishing houses "cannabalize" their back catalogs and stop printing older paperbacks when they go out of print in order to promote their newer authors and/or new "bestsellers". Ebooks never need to go out of print so it doesn't make sense to do that, but they do it anyway. They drop a book for a while, and then reprint it right when the royalty deals with the author expires, extending the deal and their "ownership" of the copyright. It's pretty shady stuff.
Read it from the indie author's view: http://www.hughhowey.com/
Hugh Howey. If you want to follow this from the author's perspective, try reading his blog. http://www.hughhowey.com/
That's the whole point. Every last one of these officers got above 90%, but the ones who (for example) got a 95% were promoted faster than the ones who got 93%. Answering one question wrong became at least a roadblock if not a career-killer, so they cheated to get 100%.
It like those "customer satisfaction surveys" that a lot of industries rely on. If you answer them correctly and accurately ("well they did the job adequately, no complaints so I give them 4 stars"), you are actually hurting the business or the customer service rep or the salesman. Anything less than "5-stars" becomes failure.
Alternative suggestion: Go to a concert. Most music is best experienced live.