I'm one of the matchers, and I can promise you that I wouldn't have given that money anyways!
This is generally a good question though; for bigger matching fundraising drives I think that more often or not the money is precommitted.
Donations reopened for the weekend, so I just made you one dollar poorer. Thanks for matching!
Singularity Institute is today's featured charity on Philanthroper.com
Philanthroper is a micro-giving site that profiles small charities hand-selected by their editors. Their site encourages donors to “give every day” by only requesting $1 contributions.
A group of Singularity Institute donors has stepped forward to match all donations given through Philanthroper today so I'd encourage each of you to give $1 now if you support Singularity Institute and have a US-based bank account (Philanthroper requirement). We'd like to have a healthy total raised by the end of the day. The fundraiser has already been featured on Gizmodo but please submit it to other news sites if you can.
I signed up and gave my $1.