So you think you’re going to see Springsteen? Here’s the ugly truth: The tour’s first 33 dates (in Jersey, Boston, Detroit, D.C., Philly, and Chicago) each sold out in an average of 30 minutes. But if you still think that playing hooky from work to camp out for the Boss is your only bet of snagging a ticket, you’re wrong. Online purchases (at Ticketmaster.com) for Bruce’s 15 Jersey shows accounted for 31 percent of all sales, while Ticketmaster outlets and phone orders tallied 43 percent and 26 percent, respectively. Camp Bruce is being tight-lipped about additional upcoming dates, saying only that the next shows will be announced in ”the weeks ahead.” (The Oct. 17 stop in L.A. announced a few weeks ago goes on sale Sept. 18.) However, each city on the itinerary has added at least one extra show (Jersey added 10), so don’t surrender your post at the ticket booth, phone, or computer too quickly or you just might blow your (last?) chance to jam with the E Street Band.