Micro-economy - what's really holding us back?

There seem to be several basic economic models that float around the
web - almost entirely in mimicry of brick-and-mortar or private
membership 'clubs.' In most every case - these leverage the
foundation of our commercial credit card systems - forcing the minimum
price of every purchase to account for the costs of credit card
transactions.

Simultaneously, we have computer and communications technology
reaching a point where transaction fees ought to asymptotically
approach 0 (ok, maybe a few cents). This implies that from a
technology standpoint we are capable of running a micro-economy, where
it is feasible to run transactions with the sales price is as low as
$0.25 or perhaps as low as a $0.05.

If we're technically capable of this, but not yet doing it, then the
implication is that a societal mindset (or apathy) is holding us back.
Or, perhaps it is the view that all "information" on the web should
be free. What does it really take to allow the micro-economy to
become an ever-present part of our daily life? And on the flip side,
do you really want it to?