At Effective Altruism Wooster we’ve run similar events with great success. As described in this EA Forum post our talks were 1-3 min long. But we’ve also run it with longer talks.
We’ve also done a variation of this with the talks being about particular cause areas and only one, longer talk per event.
Thanks for the input. I would like to hear better names for this idea.
Yes, the idea is similar to crowdfunding. I think there is an important difference though. I see conditional donations working under some form of a website that directs donations to effective charities. Donors would thus be able to set many conditions for the optimal allocation of a specified lump sum. The main gain that I see is that this allows for more optimization than in a normal crowdfunding implementation, where you might have to split your budget.