Sounds like an interesting platform; way to go!
You will need to:
1. Get the 25% secured before launching.
2. Have at least 25 ambassadors-- people willing to post and tag on your behalf.
3. A script for these ambassadors with FB posts, tweets, etc... pre-made.
4. *** Secured partnerships with nonprofits and social businesses. Why? So you can show a real use-case scenario and say that the money raised will go towards buying the first inventory that you will put on the platform and manage for the nonprofits/social businesses.
5. Send me an email (firstname.lastname@example.org) and I can connect you with the head of Grameen Check, the clothing company of the Grameen bank who could be a good partner.