"Stanford computer scientists have created a website to help organizers plan events that are more likely to succeed or allow them to pull the plug on impending flops before they occur.
The website, called Catalyst, is based on a behavioral science concept known as the threshold model of collective action, which posits that people may be reluctant to commit to participating in activity until they see others taking part, at which point interest surges and the activity becomes successful. But if participation doesn’t reach this threshold point, the event is likely to fail.
Catalyst builds this principle into software. The website allows people to enter a few details, such as date, time, description of the event and the number of participants needed to make it a success. If signups don't hit this threshold point by the deadline, Catalyst emails organizers and would-be participants a warning."
Via Howard Rheingold