Twitter-Led Recovery

Making my way back home yesterday, I noticed the following at a BWI newsstand:

(my photo, available under cc license)

This means we're in some kind of Twitter bubble, right?

In all seriousness, Davis Gelles reported for the FT back on December 23:

In the past five months, the implied valuation of Facebook, the social networking site, has risen from $26.4bn to as much as $41.2bn. Twitter, the instant messaging service, has more than doubled in value during that time to $3.7bn. The value of Groupon more than trebled to $4.8bn after Google sought to acquire the coupons site.

I like Groupon and Twitter, and obviously a lot of people who aren't me like Facebook. But would any of us be shocked if a traveler from the future told us that by 2020 one of these firms was out of business? All three?