I cannot prove it was Roku but I don't believe in coincidences. The day I signed up, added my credit card, and purchased Starz, Disney, and Qello, was the last day of low junk mail volume. The very next day, I received over 175 junk mail offers. It might not be Roku, but one of the apps I purchased. Other than signing up with Roku and making the purchases, I have no other changes.
I have no subscriptions directly through Roku. While a get a handful of junk mail I can't attribute it to Roku. I think you are more likely correct that it's one of the other services you started using. I recently signed up for CBS All Access, and didn't see any uptick in my junk mail. I would look suspiciously at either Starz or Qello (maybe both).
I might get an email a week at most from Roku themselves, and about the same from CBS.
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