Netflix shows -- in their second or third season of release -- witnessed a sharp boost in "catch-up" viewing of older, initial season episodes, according to Ampere Analysis.

For example, global viewing of Netflix shows had an 86% increase in older-season episodes in the second half of 2023 -- the time when a new season launches -- compared to the first six months of 2023, when there were no new episodes.

In comparison, when a series did not have a TV season of episodes, viewing of those older released 2023 episodes declined by 46% on average over the same period.

Overall, new releases are very impactful, the study says, accounting for over one quarter (26%) of TV season viewing hours that year. 

"However, new seasons also add value to older seasons by attracting first-time viewers and encouraging repeat viewing from existing fans," say the Ampere Analysis authors.

"Lupin," a French crime series, saw the most significant increase. When it released its "Part 3" season in October 2023, viewing hours for Part 1 and Part 2 soared to 165 million hours in the second half 2023, from 33 million in the first half 2023.

Breaking down scripted TV series from unscripted TV series, the former had past-season viewing hours double those in the second half of 2023 from the first half.

Unscripted series did not perform as well: The average unscripted show with a new season saw a 7% decline in viewing compared to the first half of 2023.

Those unscripted shows with no new season witnessed  a viewing decline of 63% in the second half of the year from the first half.

Joe Hall, senior analyst at Ampere Analysis, says: “Although new releases draw the largest viewership for Netflix, continuing series also reignite interest in older content from existing and new fans.”