Why did Kerry concede so quickly?

An article by Tom Paine in entitled: Kerry Won. I wish. Paine writes, [Greg] Palast’s investigation suggests that if Ohio’s discarded ballots were counted, Kerry would have won the state. Today,  the Cleveland Plain Dealer reports  there are a total of 247,672 votes not counted in Ohio, if you add the 92,672 discarded votes plus the 155,000 provisional ballots....Kerry won. Here's the facts. I know you don't want to hear it. You can't face one more hung chad.  But I don't have a choice. As a journalist examining that messy sausage called American democracy, it's my job to tell you who got the most votes in the deciding states. Tuesday, in Ohio and New Mexico, it was John Kerry. Most voters in Ohio thought they were voting for Kerry. CNN's exit poll showed Kerry beating Bush among Ohio women by 53 percent to 47 percent.  Kerry also defeated Bush among Ohio's male voters 51 percent to 49 percent. Unless a third gender voted in Ohio, Kerry took the state. He then goes on to list the three factors that resulted in the undercounting of Kerry's votes. This reference to the strange percentages that get bandied about during the vote counting process is of course not including the issues that have allegedly come up with electronic voting. One article documents a number of strange e-ballot behavior... Blue lemer has a story about how the e-voting machines consistently gave Bush a 5% point boost... while I am convinced that an investigation was warranted, I wish that they had included in their graphic, an example of voter polling matching up with returns in a Bush leading state that used paper voting... regardless the graphs themselves are striking...