Facebook ads have been working well for us. We create a video with a content creator demonstrating how our DTC app works (an app that helps you read ingredient labels) and run that video as a Facebook ad, tracking installs with the Facebook SDK. Averaging about $1 per download with that method.
Reddit is still super underrated. It's probably because it's not that easy.
However, once you find that grey area between blending in and plugging your solution, you're golden.
You need to find relevant subreddits, threads and comments daily though which is a lot of work so I'm using Surfkey.io by @johancutych to help me.
@johancutych@a_m4 thanks for the help, I'm a huge fan of Reddit too but as you said, it can be hard to find the sweet spot between blending in and plugging your solution!