LinkedIn is valued at about $20 billion, making it one of the biggest U.S. technology companies by market value.
How Do I get Birthday Alerts of my connections on Linked In? - LinkedIn Help Center
LNKD: Summary for LinkedIn Corporation Class A Co- Yahoo! Finance
Almost 20 years ago, when the web was young, this was a "case study" on one of prominent web sites of that time (photo.net). Helped get MIT PhD, and a few $ million VC / startup investment...
by Philip Greenspun, part of Philip and Alex's Guide to Web Publishing,
At that time simple Oracle SQL database was a back-end, LinkedIN is likely using NoSQL... Technology is advancing... Predicted the future...