mppatterson

Surprised no one has mentioned Focus at Will (https://www.focusatwill.com/). I've had huge productivity boosts while listening, whether it's programming or writing emails. The free version is nice, but the paid version is really worthwhile since you get a much wider variety of music (it adds an "intensity" option to each genre).

Most people won't simply leave if the ads are not intrusive; many of the people who are annoyed by ads will already have Adblock installed, anyway.

Did you consider having a paywall for a portion of your content?