Venture Capitalists and private investment analysts often throw out lofty numbers when talking about the value of a company, but such entities rarely make substantial investments based upon those claims. When “The Street” makes such a valuation, there is normally real money involved. Such is the case with Facebook as respected investment firm Goldman Sachs and an undisclosed Russian firm have plopped down $500 million against a $50 billion valuation. That kind of money will poise Facebook to bring in more talent, improve infrastructure, and take some risks with their monetization platform….