I'm talking about, for example, a company that sells sports apparel contracting with a company that sells sports equipment to put an ad on their website. No advertising company involved, no worries about fraudulent clicks. No javascript needed, just an anchor tag with a specific url around an image tag. The apparel company wouldn't worry about almost all the normal metrics, just how many actual jerseys did they actually sell through this ad on average per time period. If it's more than they paid for the ad, then it was a good deal to have made. It's easy to check for fraud in this scenario. They paid for the ad to be visible for a specific period of time. All they have to do is take a peek at the website to see if they are being defrauded or not. And no information about any users (other than those who actually paid for apparel) needs to be known by anyone.