It is a political drama, with Spacey as Majority Whip, Francis Underwood, the most ruthless politician you have ever seen, who knows every secret in Washington, and Robin Wright as an equally ruthless business owner, whose goals seem to fall into line with Spacey's. It's an example of "I'll scratch your back if you'll scratch mine." Until their goals clash. Kevin Spacey does mean and nasty so well, I almost liked his character in spite of it all. Almost.
Forbes describes House of Cards as a sort of "Tony Soprano meets The West Wing." I thoroughly enjoyed being able to watch several episodes in a sitting, on those long weekends of nothing else to watch.
Netflix is definitely onto something here, and we can expect other outlets to follow suit. It has to be good for viewers, and cheap at any price.