Easily solved.

If someone shows the regulator an ad for fanduel that shouldn't exist, they pull their permit to operate.

We have already seen that you can ban ads pretty effectively. I can't remember the last time I saw a cigarette ad, hell, where I live you can't even display them openly in stores, I can't even recall the last time I saw a cigarette logo.

I have yet to see any 'grey market' cigarette ads.