I *hope* spam control falls out of the economic throttles on messaging
Yes, I would send 15 copies of my memo-to-Steve-Case out to friends in
parallel: start thinking about the *over*abundant network. Possible
axiom: "Any event-notification system that drops less than 97% of
events *isn't generating enough events*" [for serendipitous anonymous
reuse to occur --- 100% event consumption is a sign of an
implicit-invocation programming model, not much more. ]
A better analogy for the link=marketplace idea hit me in the shower:
the link can be modeled as an *airline*: it has a series of hourly
flights, and it sells tickets to fill up the next one, then manages a
queue at decreasing prices. All the usual market-segmentation and
yield-management lessons might apply to modeling a channel as a series
of discrete flight-markets: 'saturday-night stayovers' for messages
that won't get reply latency bounds, "full fare" for synchronous
notifications a la fax...
Rohit