The days when shows would live or die based on their overnight ratings may be a thing of the past.

Shows these days are really more concerned with the number of tweets posted during a broadcast.

The hands-down winner in that category is ABC Family’s “Pretty Little Liars” — which became the No. 1 most-tweeted season premiere in TV history Tuesday night with nearly 1.3 million tweets.

The previous record was held by AMC’s zombie drama “The Walking Dead,” which logged 1 million tweets during its February season premiere.

“Liars” has the distinction of having the Top 4 most-tweeted telecasts of all time.

And that makes you think: are viewers thinking of ways to compress their enthusiasm about the show into 140 Twitter characters, rather than actually watching the broadcast?