Feeling the sting, he apprently had a report done to check to see if he was being misled. Sure enough: his investigators found obvious, convincing evidence of fraud, fraud that he apparently didn't notice while making regular posts on these polls for a long time.
Not only that, he took the time to write an entire book based on a Research 2000 poll (though he now claims that's not the case, per Jim Geraghty's update), an effort that surely led him to spend many hours poring over the numbers they provided him, but only now does he find out that they've been stringing him along presumably from day one.
I have two broad reactions to this: First, I was stunned at how brazen this fraud was. Research 2000 did nothing to hide their tracks. And then, later, when I thought about the implications for R2k's customer, I got a laugh. Though it wasn't a laugh quite as fulfilling as Moe Lane's.
I don't blame Moe for laughing so hard, though. Moulitsas got duped, and is now stuck with the stench of fraud surrounding the reputations of his flagship website and his new book. This was supposed to be his time, what with Democrats running the Congress and the White House. But now he's the guy whose wife is pregnant with another man's baby. He can hope the "divorce" will go his way in court, but the damage is done. Everywhere he goes now, people will look, and they'll shake their heads, thinking about how that poor, poor man was just so oblivious for so long.