(Bigstock Photo) Remember when everyone said Microsoft overpaid for LinkedIn? Nearly a decade later, the $26.2 billion “overpriced” acquisition now generates that much in revenue every 15 months. As Wall Street obsessed over Microsoft’s Azure growth rates and OpenAI accounting, LinkedIn quietly crossed $5 billion in quarterly revenue for the first time in the Redmond company’s December quarter, up 11%. That puts the business social network on an annual run rate of more than $20 billion. LinkedIn...