I wonder which pal owned that domain?
According to domaintools.com, the domain "prosper.com" was owned by A Emmet Stephenson from 2001 thru early 2006. Well, he listed the owner as "prosper.com, Inc", which means nothing, and he he was the administrative contact. I doubt that there was a business by that name. This is a common dodge to keep a low profile.
In February of 2006, the name servers were changed from lmi.net to name-services.com . This likely corresponds to the "purchase" described in the S1. However, Emmet's name remained as the administrative contact until January of 2008 at which time it was changed to Ron Pugh. The late name change may mean something, or it may have been an oversight. Domaintools says Emmet owns 136 domains, but it wants money to let me see their names, and I declined.
Looks like Emmet has done well with his domain name investments. I have not done so well. I have a dozen or so names. Once a guy offered me $25 for one of 'em.