More than five million viewers tuned in to watch this year's launch of "Love Island".
The reality TV dating show is now ITV2's most watched show ever, and the programme has also beaten off competition from the likes of BBC dramas "Poldark", "The Split" and "Versailles".
A TV source told The Sun's Bizarre TV column: "Everyone at ITV hoped it'd grow, but they're chuffed how much it has done.
"It's by far the most successful show in ITV2's history and is the biggest audience on a digital channel since the Olympics on BBC Three in 2012."
The first episode drew in a combined 4.1 million viewers over the course of seven days and a further one million via the ITV Hub on tablets, smartphones and computers.
ITV said in a statement: "Only "Britain's Got Talent" on ITV main channel has had bigger audiences for this demographic on any channel so far this year."
However, the show hasn't proved popular with everyone.
"Dancing on Ice" judge Jason Gardiner recently hit out at the programme, claiming the series is a "fast-track to stardom".
He said: "It's amazing what people will do in order to be famous.
"In my day you were a celebrity because you were good at something.
"Now it's not about being inspirational or having a special talent.
"It is literally about their love lives. You watch them do it, sex on an island.
"It is like a fast-track to stardom."
His comments came days after The Apprentice's Claude Littner - who acts as an aide to Lord Alan Sugar on the BBC business show - slammed the show as "soul-destroying viewing" and described the contestants as "completely brainless" and "self-obsessed".
In a series of tweets, Claude wrote: "I'm going to take one episode at a time. It is soul destroying viewing, but I will not be deterred!
"Unfortunately it is a marathon and not a sprint. Honestly, I don't know how much more of this I can bear. It is beyond doubt the worst tv programme.....and yet.....I am still watching!! (sic)"