You make good points, but I think we agree on the core. There are challenges with a pay for performance model, but a business that successfully operates on one

You make good points, but I think we agree on the core. There are challenges with a pay for performance model, but a business that successfully operates on one is sending very strong evidence that they are actually effective. A fee for service program may or may not be good, but the burden of proof is now on the company that they are worth what you'll spend on them.