Display ads are fine, but they leave most of the value of YMYL traffic on the table. The real money in hard niches is on the back end, where it recurs. Three models that work: a subscription or membership tied to the problem you rank for, recurring affiliate offers (SaaS and ongoing services), and your own productized service sold to the exact visitors you already attract. What does your back-end revenue look like today, and where's the gap?