If your goal is to force every player to be less selective in their social networks, then yes, small servers do that. If you want people to find a good critical mass of people that share their interests, play-style preferences, and online schedule, you need larger server capacities.

Or check out this call, fits your experiment perfectly (though its admittedly a tad wordy)

“Digital Game Play as Sociotechnical Practice

September 02 2010 | Trento, Italy

Deadline: March 15 2010

http://events.unitn.it/en/easst010/abstract-submission

The Digital Game industry has become one of the fastest growing,
innovative and globalised industries in advanced Western economies and
Digital Games have become a key cultural artefact and leisure practice
in contemporary societies. Developing out of the American military
industrial and academic complex in the 1970s the study of Digital
Games design and play is the study of a range of sociotechnical
practices and the negotiations between a range of human and non-human
actors operating within systems of rules. The complexity of these
relationships brings forth a series of questions that can be
investigated using Science and Technology Studies approaches. However,
to date games studies, with few exceptions, have failed to adopt STS
approaches and the STS community has largely ignored this area of
study.

This track seeks to develop the relationship between the game studies
community and the STS community. Several research questions can be
used to guide this: What STS theories can be used to understand
Digital Games as sociotechnical phenomenon? Is the concept of practice
and the practice-based approach useful to investigate Digital Games?
Is there a relationship between power as inscribed and imposed by
artefacts and the technical dimensions of Digital Games? What rules
are inscribed into Digital Games technologies and what social worlds
do these rules describe? What contribution can the study of Digital
Games make to the STS discipline at large? And what contribution can
an STS approach make to game studies? Can we foresee an after-method
approach for Digital Games? We invite papers that tackle the
sociotechnical dimensions of Digital Games and address some of the
questions outlined above. Contributions might include (but are not
restricted to):

• Digital Games as material semiotic artefacts
• Digital Games as sociotechnical assemblages
• The mess of digital games
• Innovation in game design as actor-networking and social shaping
• Digital Game design and/or play as performance and practice
• Disruptive sociotechnical users’ practices (e.g. hacking, modding)
• The scripting of gendered gaming practices
• Governance and regulation of gaming practices

Abstracts of no more than 500 words should be sent by email (following
website instructions:
http://events.unitn.it/en/easst010/abstract-submission by 2010 March
15th. Please include also a preliminary references list (up to 4).
Contact for inquiries: stefano.depaoli@nuim.ie

The Bernard-Killworth researched numbers make more sense to me, somewhere between 230-290 for personal networks.

This is just one reason I’ve always been boggled when MMORPGs have this obsession with adding more and more players per server.

In my experience, smaller servers tend to create stronger communities. Better networks between players, so it makes sense.