Our ad run on Overcast app. came to a close on the 21st and by their standards it was resounding success. They state an average of 20–30 subscriptions with a $5.20 cpa (which changes depending on the floating cost of the ad).
We ended up with 57,913 ad views, 603 taps (1.0%), and 57 subscribers (9.5%). As far as I know, it’s not possible to track how many subscribers became listeners, or if they unsubscribed immediately after. This makes it difficult to determine the efficacy of small ad spends.
With our current monthly downloads on Sleep Tight Stories north of 550,000 per month, 57 new subscribers won’t have any marketable immediate effect. Having said that, I do see this as a far more effective use of a limited advertising budget than say Facecrook, or Google. Google Adwords is a complicated morass of options that requires time to understand.