Potentially millions if Tucker Carlson can‘t pick up the audience left behind at the 8pm timeslot. With O‘Reilly‘s :30sec spot going for $16-$20K (peaking in the last 6 months at as much as $28K p/:30) there will be a lot of ground to make up.
I think it is too early to have a clear answer to this, but based on how Carlson has done at the 9PM slot, I think it is likely that he will be able to increase his current 9pm average unit price, but it will still be less then O‘Reilly‘s out going avg.
There is the possibility that advertisers will like him more as a show and personality that aligns with their brand values, but there is no guarantee that personality will translate into viewers. That will be one, if not the biggest, concern for the network moving forward. If Fox can sell viewers and advertisers on Carlson, maybe he can win back more of that revenue that has been streaming away since the recent revelations.