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Re: Internet provider tells me they don't support Roku. How can that be?
I think @DBDukes nailed it. I believe they are referring to their StreamTV service as being natively supported. Although the Rainier Connect is still available in the Roku Channel Store https://channelstore.roku.com/search/rainier it doesn't seem to be supported according to the Rainier website info.
Although their StreamTV service may be unavailable to you, you should still be able to use a Roku Streaming Player plugged into your TV and connected to their internet service. You would simply use it as any ordinary Roku user would (without potential access to their StreamTV services).
Roku Community Streaming Expert Just another Roku user... I am not a Roku employee.