Implementing rewarded ads on top of in-app-purchases

Ideally I’d like to increase revenue by allowing users who do not pay for IAP to view a rewarded ad and get the same content for a limited time. My logic is, if they’re not going to buy anything, then might as well give them an option to watch an ad, and I can still make a little revenue from that.

Anyone have experience with this? Did it work out? Did it eat into your IAP revenue?