The old rule of thumb of the newspaper business was that each letter to the editor represented 1,000 readers with the same view.
I don't know what the updated rule looks like for emails to the editor. Probably not very different.
So the New York Times got 400,000 readers angry at them for the despicable MoveOn.org ad they ran nearly two weeks ago (based on the 4,000 angry emails they received). That is roughly 40% of the total New York Times readership.
Forty percent is also significant because that is the discounted amount the NYTimes offered on their regular ad rate to accommodate MoveOn.org. Only 40% of their regular rate. MoveOn didn't even ask for the 60% special discount. Which the Times would not make available to an anti-MoveOn ad.
We also know from the Time's ombudsperson that the Lefty meanspiritedness was not only found in the sales department that offered the ad price, it was in the ad review department where a department head violated the Time's written and explicit policy against ads with personal attacks. This was an ad with a headline that had the most offensive personal attack anyone can make on a soldier: betrayal.
Lets not forget that the ad did America a favor. It focused the Iraq War debate on the McCarthy-like nature of the anti-War activists and it put Hillary and Obama on record as defenders of McCarthy-like behavior when they failed to join a Senate Democratic majority in opposing the MoveOn-Times calumny.