That's right, as far as I know; it's sales commission as opposed to the warehouse model. I meant $50 more than you might pay by shopping among competitors: Amazon might not have the best price but you've derived value from the person's detailed insight into why it's a good purchase, plus you'll get Amazon recommendations for other purchases from people whose reasons for purchasing are similar to your own, which is also useful.

My point was that while the revenue is intermittent rather than a steady trickle, the intermittent rewards are individually decent - which dovetails nicely with occasional but high-quality content updates rather than drip content + SEO.