It had appeared that Sony had got one over rival Microsoft when it announced earlier this week that the number of registered users on PSN has passed 20 million – but Xbox Live has to date made over five times as much money as Sony’ service.

That’s the claim from the Variety blog, which reports that whilst PSN revenues total $180m, Xbox Live revenues total over $1bn.

There are several variables that make the numbers more or less impressive, of course. For starters, Xbox Live has been around for 67 months and PSN just 27 months. And, of course, Gold members of Xbox Live (which currently number around nine million) pay £40/$50 per year for membership, whereas PSN is free.

Many commentators have, following Sony’s release of its user numbers, pointed out too that many users have multiple PSN accounts to enable access to content on the Japanese and North American versions of the service.