The letter from Facebook founder Mark Zuckerberg surely ranks among the most fatuous CEO missives in recent history, easily outdistancing Google's "Don't Be Evil" mantra.

For all the talk of improving human connection's, Facebook's business model depends squarely on advertising. As one math genius out of Harvard put it memorably in a Bloomberg Businessweek story last year:

That said, like Google before it Facebook is one of those transformative businesses. It is the prime mover of the Web 2.0 world, and the fortunes of dozens if not hundreds of other companiesare closely tied to its success.

Will its growth continue at the same pace? No, though it's anybody's guess at this point as to when it will slow. But slow it will, as Google and Amazon have learned.