I met the native guy recently at a conference. He's seriously one of the most impressive stories I've ever heard - 2 years, 1 product, only sold on their site, 100M exit, vast majority going to him. He talked about testing a ton of variations (over 100 overall) of their product by selling batches of a couple thousand and tracking return rate, reviews, and reorder rate. Get the best product after extensive customer testing, get the best ads after extensive a/b ad testing, scale up profitable ad spend.