There are a whole bunch of assumptions here:

• that we want people nearby (and for that, you need not just nearby-ness, but knowledge of presence)
• the computer desktop is a "place", that you already have some kind of presence beyond the screen (required for the metaphor of agency, I guess)
• the importance you give something is proportionate to the size/effort of the interaction (the cognitive cross-section has to be consistent)
• that groups have an identity that is greater than the sum of the pairwise relationships between the individuals

And that it's worth having an application that is

• used for bonding with existing friends, not making new ones. I have enough friends. I don't want more, I want these ones better
• non goal-directed (atellic). I use Outlook quite enough already
• made for communication almost devoid of semantic meaning. Like going to the pub

2003-09-14