In just seven months after launching their streaming service in the UK & Ireland to compete with European heavyweight Lovefilm, Netflix is announcing a pretty big milestone:

UK & Ireland Netflix members now total over one million. Netflix says that this is the fastest that any territory has ever hit one million users.

“This membership milestone is evidence that Netflix has rapidly gained popularity in the UK and Ireland,” said CEO Reed Hastings. “Our British and Irish members clearly enjoy the ability to instantly watch a large variety of TV shows and films streaming from Netflix on their favourite devices whenever they want.”

Netflix also boasts that this achievement propels them ahead of the early milestones of other prominent companies, for instance 1 million members in seven months is four times faster than Twitter’s preliminary growth rate. And its double that of Facebook and Foursquare.

To be fair, I’m not really sure what Foursquare’s global member growth has to do with Netflix’s growth in a new market, but Netflix seems to see a comparison.

Two fun facts about Netflix’s fast-growing UK & Ireland audience: Their favorite genres are comedy and drama, and Sunday night is the peak night for streaming activity.

Last week, Netflix announced that they were expanding into another market later this year: Scandinavia. Netflix says that before the end of 2012, their streaming service will be up and running in Norway, Denmark, Sweden, and Finland.