Ok, as I was suggested, here is a correlation between my "amazon most wished for items" points vs actual sales. Thank you to the guy who gave me the idea (I can't read his name for some reasons...) :)
For sales, one point = 1k
PS4
Not too bad, but small spikes are not detected.
XBO
Pretty good to some extent, rise in points usually precedes rise in sales.
WiiU
Very Good so far... :)
3DS
Completely off as expected in absolute values. May be ok for trends but it remains to be seen... Let's wait for this christmas 2014 100$ smash bros bundle... :)
Vita
Not too bad either.
Well, so far, exept the 3DS, I am rather nicely surprised by those correlations. What do you think ?
PS: Please, if you quote this post, erase the links for readability purpose... :)