Extras is filmed in a more traditional multi-camera sitcom style, in contrast to the mockumentary style Ricky Gervais and Stephen Merchant used in their previous series The Office.

Jude Law was originally scheduled to appear in a series 1 episode after meeting Ricky Gervais backstage on the Late Show with David Letterman, but had to pull out due to film commitments.

After Jude Law dropped out, Gervais and Merchant doggedly pursued Leonardo DiCaprio as a replacement guest star, an unsuccessful chase documented in the series 1 DVD featurette 'Finding Leo' filmed mostly by Merchant at night.

Jude Law's role was ultimately filled by Patrick Stewart in the series 1 finale, though a poster for Law's film Alfie can still be spotted at the end of the episode.

Gervais had initially reported that Madonna, Brad Pitt and Tom Cruise would appear on the show, but none of them ended up featuring in it.

Ventriloquist Keith Harris turned down a guest role after reading the script, telling The Independent, 'This isn't clever writing, it's pure filth'; Keith Chegwin appeared in his place.

The show's closing theme is 'Tea for the Tillerman' by Cat Stevens, while the second series' fourth episode features a cover of the song performed on-screen by Chris Martin of Coldplay.

The Christmas Special uses Kate Bush's 'This Woman's Work' to underscore Maggie's depression, and The Smiths' 'Please, Please, Please, Let Me Get What I Want' plays during a scene of Andy's bad evening at The Ivy restaurant.

The show-within-a-show, When the Whistle Blows, satirises catchphrase-driven British sitcom hits like Little Britain and The League of Gentlemen, with audience members at its taping wearing T-shirts bearing real catchphrases such as 'Am I bovvered?' and 'Garlic bread?' (though these shirts were cut from the US broadcast).

Andy Millman's fictional sitcom also nods to 1970s British comedy through references to catchphrases like Mr Humphreys' 'I'm Free' from Are You Being Served? and Frank Spencer's 'Ooh Betty' from Some Mothers Do 'Ave 'Em.

Extras holds a Metacritic score of 81/100 and received strong critical acclaim overall.

Ricky Gervais won the Primetime Emmy Award for Outstanding Lead Actor in a Comedy Series in 2007 for Extras, having also won the BAFTA for Best Comedy Performance that year.