Thanks! But that's not exactly how the setup works. We have a licence fee around US$200, that goes into funding the BBC and only the BBC. As a result the BBC doesn't run commericals, none at all.
Then we have the other channels, terrestrial broadcasters such as ITV, Channel 4, and satellite/cable like Sky. They get no licence fee money, they are funded by commerical advertising and/or subscription.
There's a very clear seperation between licence fee and no commericals, and no licence fee and commericals. One doesn't subsidise the other.