You are totally right. If it wasn't because they out of nowhere popped in here telling me about this new feature, I would have never know about them. Even in this post there is only 1 tag...

Good for you for giving proper support to them. They clearly need a little bit of advises on how to get known in this platform, because what they are offering is quite cool actually.

As far as I know, the only promotion they are doing is leaving comments on people's posts announcing they converted it into an audio, and while this is ok, I think there are better ways for them to get noticed.