I made almost 6 figures a year on an affiliate website promoting natural health products, when they were extremely popular back in 2006.
I would stay awake some nights and jot down every product mentioned in overnight infomercials (before I knew what TiVo was). then write a review on them the next day.
Thousands of people would search for “X review” in the days after watching those infomercials and I would rank #1 because some of them were brand new products.