newsletters and expanding subscriber lists. I mentioned including flash/short stories in those newsletters. Since readers sign up to read my works, I figure one-off shorts are a great way to thank the readers for supporting me. The short is most likely from a POV of a character who didn't have that honor in the main book--say a side-kick or an unnamed character the main book's protag noted in passing. It captures just a moment, a scene, a different perspective that hopefully entices readers who haven't yet purchased the latest book and rewards those who have.
Until retailers allow self-pubbers to create coupon/promo-code campaigns, short stories are the best way I can think of to thank my readers.
And to those of you reading this blog, THANK YOU.