Niel ‧ sen Rat ‧ ings, the /ˈniːls ə n ˌreɪtɪŋz/ BrE AmE ( also the Nielsens ) trademark
a system used to show how many people watch a particular US television programme, using information provided by Nielsen Media Research. The Nielsen Ratings are used to decide how much companies will have to pay to advertise their products during a particular programme, and they also help television companies to decide which shows should continue.