MOUNTAIN VIEW, Calif. (AP) '� LinkedIn and Facebook will celebrate the anniversaries of their IPOs just a few days apart this week. But their experiences as publicly traded companies couldn't be more different. LinkedIn Corp. promotes its service as a stepping stone to a more enriching career. As it turns out, the professional networking company's initial public offering was a great place to start a rewarding investment portfolio, too. LinkedIn's stock has nearly quadrupled in value from its $45 IPO price on May 20 two years ago. On Monday, it closed at $175.03 per share. In contrast, Facebook's stock is hovering around $27 per share, down 29 percent since debuted on May 18, 2012 at $38. LinkedIn is emerging as the standout performer among its cohort of hotly anticipated IPOs from Internet companies that connect people with common interests. The company is growing faster and yielding far better shareholder returns than the rest of a class that includes onl...