So what’s illicit about it, compared to the usual ad business?
I.e. as far as I understood the particular situation described by OP, the breach of contract happens between the site and network, not between the network and advertiser.
Same thing as this article, but without actually building the technology themselves, simply being the middleman.
They’ll be upset if this “gray” traffic doesn’t convert well, but Lexus buyers just might be the type with the disposable income for gambling.