This was mentioned the last time a similar thread came up as well. Reputable, large corporations don't tend to work that way. A department will often end up doing their best to provide a service to a competitor of a different department.
The point is that innocent statistics about Netflix's machines gathered for routine "security" and other housekeeping efforts can lawfully give Amazon a lot of information about Netflix.
IMHO, Netflix has needlessly put themselves in a vulnerable position by moving to Amazon.
Google has every bit of information about Groupon and LivingSocial AdWords spending (millions of dollars per month). When Google launches their competitor, Google Offers, they'll know exactly which ads get people to buy deals. Incidentally, Google Offers will work by running offers across Google ad networks.