In November, First Round Capital VC and blogger Josh Kopelman bought a pair of ads on Facebook targeted to the Yahoo and Microsoft networks, asking "Leaving Yahoo?" and "Leaving Microsoft?" Clickthrough rates were low. Only 0.3 percent clicked on the Yahoo ads, and the Microsoft ads drew no clicks at all. But after Microsoft's recent $44.6 billion offer to buy Yahoo, the companies' employees seem more eager to leave. Now, 0.86 percent of Facebook users who saw the Yahoo version of the ad clicked, and 1.19 percent of Microsoft employees targeted clicked on their ad.