How much is social worth to Google? Investors added $20 billion to Google's market cap the first week after the launch of Google+ on June 28. A Morgan Stanley downgrade on Friday, brought the total down to $15.8 billion because of doubts whether Google will indeed be able to capitalize on new products such as Google+. But somewhere in between there, give or take a few billion, is how much more the market thinks Google is worth than before the launch of Google+.