I can give you an example of an information market that seems to operate in the same manner: bond rating agencies. I took a class that was taught by a seasoned finance veteran and he told us a story about when he ran the municipal bond desk at his agency. As it turns out, at his and every other finance company he knew, nobody gave any credibility to bond ratings when deciding to invest. Why would they? He told about the time that he called up one of the [well-known] agencies to talk about the rating process and was surprised to discover that they had a grand total of 15 employees for municipal bond ratings.
How are 15 people maintaining accurate ratings for the tens of thousands of municipal bonds??? How can they provide value commensurate to the amount they charge to rate a bond? Well, actually... They don't actually directly charge that much money. The big cost is borne by the city issuing the bond in the form of higher interest rates. But why would a city pay money to have a worthless rating that forces them to pay higher interest rates?
If a city sells a municipal bond and nobody shows up to the sale, did they really sell a municipal bond? Access to the marketplace is the difference between not selling a bond and selling a bond at a high interest rate. The gatekeepers to the marketplace want to have reasonable confidence that the bond is not a scam and reasonable confidence that the bond was issued in good faith. They also do not want to be in the position of deciding which cities should have access to the marketplace. So they've made a simple rule: any bond that gets rated by an agency they recognize can have access to the marketplace. The "value" of the bond rating goes mainly to the companies that make up the marketplace. The "cost" of the bond rating is paid by cities issuing bonds.