Why Always Ste said:
Isn't the reason UEFA are happy with BT is also because BT can provide access to free to air to everyone in The UK, whereas with Sly Sports only people who can watch The CL on SS are subscribers of Sly... advertising revenue will skyrocket for these games if shown on BT rather than Sly.
Absolutely not. UEFA are hugely biased against free-to-air broadcasting. They hate it. The revenue from TV companies buying rights to the games is far more important to them than the amount of viewers looking at the sponsors - after all, the sponsors pay them to get their names on the boards, so it's the sponsors' jobs to actually make money off their brand awareness, not UEFA's.
Remember that it took an Act of Parliament to prevent UEFA dictating that all England games had to be broadcast via subscription-only channels, and even then there was talk of UEFA putting a boycott on England if they passed the law, though they wimped out in the end.