Craig and others, there seems to be little question that the primary revenue stream for coworking communities is
work space memberships. After that there has been a hodge podge of experiments within each community to see what works best, most efficiently and for the greatest benefit to the space and its members. At Mojo, our second biggest stream is meeting space - mostly conference room rentals for non-members. We also do printing for local business and believe that this can become a significant profit source. (we lease a printer and pay 1¢ for black prints and 10¢ for color ... we charge 5¢ for black and 35¢ for color to non-members. We just did a 3,500 page print job ... the math is pretty simple there.
The trick I find is to keep it simple. Do what is best within the limits of your current system resources and then look for "plug ins" that don't over tax your time/energy ... but can deliver benefits to you and your membership.
A few of you mentioned local sponsorships as a revenue stream. The trick is finding the right sponsors (who fit your member audience) and also having the resources to deliver what they expect in a professional/meaningful way. It can be done, surely, but it'll be important to look at the cost/benefits of each.
I'm beginning work on an idea that I think offers a better solution to tapping sponsorship as a revenue stream for the coworking movement. I consider it a "plug in" for sponsorship. Instead of each coworking space identifying and negotiating with local sponsors, We've started to build a network of coworking spaces and will facilitate the relationships with national level sponsors on a larger scale. By creating a more complete national footprint we can attract bigger companies with brands that have an authentic fit with the coworking movement and will inject energy and value into the membership at each space. Think Intel, Apple, Cartoon Network/Adult Swim, Converse, Acer, REI, Prius, Cannondale, Canon, Belkin, Clif Bar, 5 Hour Energy Drink, etc. Having larger/national sponsors should also provide higher "sponsorship fees" to coworking owners - and demand less time/energy to activate.
I guess I should mention that my "day job" is running an advertising agency with multiple Fortune 500 clients who are looking for this sort of experiential connection to the smart, young, entrepreneurial audience.
Our network concept is just getting started, and I plan to have more details to present at GCUC, so I'd love to hear any feedback on this idea as well as talk with anyone interested in possibly joining our "network" of spaces.