TweetDeck, arguably the most popular Twitter desktop client today, looks like it will be going from strength to strength after securing an investment of $2 million. He revealed the investment to TechCrunchs’ Mike Arrington during CrunchUp.

The question now is how do they recoup this investment. They recently released a TweetDeck iphone application which proved to be very popular, however it was released for free. Perhaps future versions of the software will have advertisements integrated. i wouldn’t be too surprised if they used the money to invest in a premium version of the script to sell to businesses and professionals.