I suspect it was added by 1.0 as that's when "the htbin stuff is no longer distributed, CGI/1.0 versions of your old favorites are included instead", but definitely exists in the 1.1 snapshot on github.
It was modified or removed at some point later on, after complaints from Jimmy Johns about abuse.
Though then it's a question of what "sold online" means, vs. "ordered online".
Yeah, I can well believe it's easily abused!