I find it that quite unethical. It's no different than paying Reddit commenters for mentioning it.
Ignoring the fact that the Xbox One has been selling great, isn't that more or less the point of marketing? Make a product seem popular, generate buzz, make money?
http://en.wikipedia.org/wiki/Astroturfing
Edit: I am a bit shocked to see so many people (well, accounts) arguing astroturfing is OK, it used to be despised and big news when Microsoft did it then. http://en.wikipedia.org/wiki/Astroturfing#Incidents I will assume that is more astroturfing. Otherwise, goodbye Internet as an information source....
If you're dumb enough to believe 'free' advice you pretty much deserve what you get. Remember when the service is free, the product is you.
Our entire society is astroturfed whats possibly more sad is that people can get genuinely caught up in these campaigns and start spreading them for free.
No, looking from the "what I expect" perspective, most people expect these bloggers/youtubers to reflect the "opinion of the crowds" and to reflect reality more accurate I guess. In this light, Microsoft's attempt to pay them could be seen as unethical.
Personally I never trusted of these bloggers/youtubers so I'm far from shocked with this news. I expect them to be doing that by the very nature of their "jobs", if not for direct profit from vendors, then for ad-click revenue.
I'd say don't be naive with anything, specially things involving products and revenue.