““At L2, we track migration patterns between the largest firms, including traditional agencies and the Four. WPP is the world’s largest advertising group. Some 2,000 of its former employees have migrated to Facebook or Google. By comparison, only 124 former Facebook or Google peeps left to go work at WPP. Consider the reverse migrants—124 that went back to WPP. Many of them, it turns out, had only interned at Facebook or Google, and went to WPP when they weren’t extended offers in Palo Alto or Mountainside.21 The ad world today is increasingly run by the leftovers. L2 Analysis of LinkedIn Data.””