Currently the value a Viewer gets from a subscription, is the attention from the streamer and the access to more emotes and to be able to chat in sub mode. I believe that Viewers who have been subscribed for a certain amount of time should be rewarded for their patronage by introducing some branded "swag" (swag refers to merchandise ) they receive to their doorstep. Sending out a letter that contains some stickers with the channels name on it and some twitch stickers will incentivise Viewers to subscribe for a long amount of time ! Creating revisions of these stickers will then further more incentivise a Viewer to stay subscribed. Then for the really long term subscribers you could up the anti so to speak with regards to the rewards.

This is my idea, curious to see any feedback. Very much want to get involved with creating value for my Viewers.