I heard about audm on some podcast, I forget where. I checked it out, and decided it wasn't worth $8 a month to have a human read to me, instead of a robot, a small subset of the content I regularly consume.
Robot-for-free over human-for-pay seems like an apt analogy for our time.
At any rate, I like trials, and if your service is truly great and had the value-add of curating excellent articles from sources I wouldn't normally find, that might put me over the edge. Then again, I cancelled my Audible subscription too.
If you're successful, Amazon surely will buy you.