From Zero Hedge:
A company whose value is dependent on the continued success of two key products, now has a larger market capitalization (at $542 billion), than the entire US retail sector (as defined by the S&P 500).
Apple sells computers of various sizes. These makers of general-purpose machines have reached a symbolic milestone in passing the retail market cap. This has to do with stock strategy and market valuation as well as other complicating factors, so we can’t read too much into it. But it’s easy to imagine a company like Apple eventually selling more computers than the world sells non-computers. The everything box ultimately encompasses all other products.