Twitter is rolling out its ” Nielsen TV Twitter Rating “ system in the US today. The metric was first announced in 2012 , and was developed in partnership with TV ratings tracker Nielsen . It will show both the number of tweets mentioning specific shows, and the number of accounts those tweets reach. That second statistic is of particular importance to Nielsen, Twitter, and advertisers. The New York Times calls actual tweets about a show “the tip of the iceberg,” and quotes Andrew Somosi — chief executive of SocialGuide , acquired by Nielsen in late 2012 — saying “the full iceberg is the extent to which people are seeing those tweets.” The New York Times uses the example of Breaking Bad ‘s finale.