I currently have a car for sale on Cars.com and Craigslist. I constantly get requests for Vehicle History Reports, always from a different VHR site, all that you have to pay for. I have in my add, a link to a VHR, but they demand that I get one from their site. They often state that their lender requires a report from this site. I always respond, "no, if you want a report from one other than what I have linked, that report, and purchase thereof is on you". Everyone of them, so far, I have never heard from again.
Personally, I think it is just a scam to get people to go to their site and pay.