How do they know how many watches a TV programme?

[Blackandpurple]

Line of Duty last night had 7.8 million viewers. Is is down to the technology in SKY etc?

I remember yrs ago (back in the 90’s) they had figures but no no ever asked me what i watched nor anyone I know!

I read years ago that tv's have some sort of device in them that tells what channel your watching

Fantastic bit of statistics, and live time is incredible, as you can see what makes people turn off/over. That's how some channels can tell which tv presenters are pulling in the viewers and which aren't (pay attention the One Show).

Oh good! I shall continue my speedy channel switcharooney then!