Open Source Developer Exchange

Hi all,

I'm interested in starting a compay similar to what Cosource
(http://web.archive.org/web/20010708093616/www.cosource.com/)  used to
be (with some differences). Specifically, an exchange where buyers can
sponsor development of features for open source projects. The company
would make money by taking a percentage of the fee paid.

There's nothing new here and in 2000 there were several companies trying
to do this (and several write-ups including
http://www.linuxworld.com/linuxworld/lw-2000-10/lw-10-matchmaking-p2.htm
l). However, they all seem to be dead now. One exception is
rentacoder.com which doesn't cater to open source business. So, why did
these companies fail?

Thanks in advance,

Sincerely,
Ron Lancaster
St. Paul, MN