I find it interesting that the number of Amazon-related articles in the Washington Post seems to have increased since Jeff Bezos' purchase of the Post.
So your theory is that Bezos spent $250 million of his own money to buy the Washington Post so that he could get more coverage of Amazon in one newspaper?
I would see it more as that maybe the employees of the Washington Post may be posting more Amazon related stories in an effort to do what they think will make the new boss happy without finding out if that's what would make him happy.
I think that's more of a coincidence than a real conspiracy. Bezos has a lot more to lose than to gain if he were in fact pushing these types of articles.
Note that Zappos is owned my Amazon.