Well, I am not a member nor leader of SCP, but as a supporter, I can give you a brief idea of the purpose of SCP. The below link is a link to the SCP group page on Prosper, most of it is explained there.
http://www.prosper.com/groups/group_home.aspx?group_short_name=SCPThe thing to note most of all as a member of SCP is and it's "benefit" to you is:
"We would like to extend a welcome to borrowers including higher risk borrowers who deserve a 2nd Chance when the time is right. Not looking to bail anyone out. Basically, we would endorse higher risk candidates looking to improve their credit rating because they can put their financial woes behind them."Given proper verification and documentation by the group and it's leaders, they may opt to endorse your listing.
I personally, am a group leader as well. While my group doesn't have near the supporting lender base as SCP, my group is strictly for High Risk borrowers that are consolidating their debts. I take the time to review their financials, monthly budget, W2, pay-stubs, and alternative credit report. I perform a debt disclosure on every borrower and then decide whether or not I feel they are capable of making their payments. I have helped 3 borrowers in the last 2 months, that had tried numerous times to get funded, all of their attempts failed. Upon joining my group, and with my endorsement on their listing, they were all funded on their first listing attempt with me, and I hope, I have choosen wisely.
The purpose of a group in general, depends on the group. Many are regional groups, or company groups, IE Microsoft Employees or Texas Borrowers. Other groups look to evaluate and endorse individual borrowers and generate a following based on their group rating. Another example is LendersClub. LendersClub is a group for lenders only (you must have $500 invested in Prosper, if you wish to take out a loan as a member of LendersClub). LendersClub has a very high group rating as all of it's 15 loans made are current, none have defaulted and therefore it is rated as 5 Stars by Prosper and attracts other groups and other lenders to bid on group loans.
Hope that answers your question.
BAEVentures