Social TV startup Miso secured an additional $4 million round of funding led by Khosla Ventures, with participation from existing investors Google Ventures and Hearst Interactive Media, bringing its total investment to $6 million.

This round follows Miso having entered partnerships with DirecTV and AT&T’s U-Verse that connects it with the TV receiver, so that it knows not only what the viewer is watching but where in the program the viewer is, without the need to check in.

That enables Miso to go beyond badges, leading it to develop synchronized experiences like the one it created in partnership with Showtime’s Dexter.

“People are changing the way they watch television,” said Vinod Khosla. “They are also on their phones and tablets, and this creates new opportunities for innovation in the second screen space. We feel that Miso is leading the way.”

Miso said it currently has about 250,000 active users.

Related links:

Miso’s blog post –