A mirage is not a hallucination, but a misinterpretation.
Facebook, for business, is a mirage.
Can it successfully gather a crowd to hear a band perform at a bar?
Absolutely. Social media, social event.
Can it successfully be used by a physically-existing retail or service business as a substitute for mass media?
No. It cannot.
I defy you to find a physically-existing business who enjoyed success prior to 2003 that is now reducing its mass media budget because it has found Facebook to be a more effective use of ad dollars. You will find no such example. I've been looking for 3 long years.
When you see the power of Facebook to connect people together, you are facing an indisputable fact.
When you assume it's "the next big thing" for business, you are seeing a mirage, an illusion, a reflection caused by hot air.
(Adapted from the article "The Facebook Mirage, YouTube, PayPerClick and the Superbowl. Rambling Thoughts, Spoken Plainly, Certain to Irritate Someone, Somewhere" by Roy H Williams, the Wizard of Ads)