The £2.2bn action replay!

They used to be pointless and plotless affairs designed only to milk more money from film fans. But now the sequel is back and its worth billions.

Four out of five of the summer's topgrossing movies in the US were follow-ups, with wizards and web-slingers propelling ticket sales to a record £2.25billion.

Shrek 2, Spider-Man 2 and Harry Potter And The Prisoner of Azkaban were the most successful films in cinemas between May and September.

In fifth place was The Bourne Supremacy, a sequel to The Bourne Identity. Only disaster movie The Day After Tomorrow in fourth place was an original.

Shrek 2 took more than £245million - making it the third most successful movie ever in the US. Spider-Man 2 earned £208million and the third Harry Potter film made a total of £140million.

But despite fans returning to catch up on the next instalment, many of them were only 'reasonably satisfied', according to Marc Shmuger of Universal Pictures.

'I don't think that cinemagoers were extraordinarily satisfied but, at the end of the day, reasonably satisfied is not a terrible report card,' he added.