Putting the zing in Zynga

Facebook insiders will become fabulously wealthy when the stock finally starts trading publicly in  a few months, but for now the biggest winners may be Zynga shareholders. Shares of the social gaming company soared more than 15 percent on Thursday, after Facebook revealed in its S-1 that Zynga represents 12 percent of the social network’s revenue, thanks to sales of virtual goods in Zynga games. I’ll have more on the Zynga connection means for Facebook in tomorrow’s Weekly Update. But for now, ZNGA is enjoying its best day since going public last year.