Why is it that Jerry Seinfeld, the American actor who had a hit 1990s TV show named after him, is always smiling? It could it be because he is party to a little secret that has just been disclosed – that his show, Seinfeld, has made $2.7bn (£1.8bn) in repeat fees since it went off the air 12 years ago.

The astonishing figure was revealed by Barry Meyer, chairman of Warner Brothers Entertainment, which has the rights to the Seinfeld series. He told a recent conference in New York of potential investors in Time Warner that the company's backlist of titles was a "library that keeps on giving".

Hollywood Reporter notes that Meyer went on to list the earnings that have been made from Seinfeld on repeats in addition to the sums the show made from its original run of 180 episodes over nine years. In total, Seinfeld has raked in $2.3bn in reruns on regular TV channels and a further $380m on cable.

As the New York Post commented, both Jerry Seinfeld himself and his co-creator of the series, Larry David, are entitled to a proportion of earnings as part-owners of the title, though it is not publicly known how much that is worth. But with sums as huge as these, it does help explain why Seinfeld is always smiling – and make you wonder, in reverse, why David is so grouchy in his current persona on Curb Your Enthusiasm.