You're being duped.
You're doing 100% of the work for the POTENTIAL of 10% of the profits.
- How will the site be marketed?
- How much money will be spent on marketing?
- Whose money will be spent on marketing?
- What is the target market?
- How much will the services be sold for?
- Who collects and distributes the money?
- How long between the time a customer pays and the time you get your 10%???
- Who OWNS the software?
- Who's going to run and control the web server?
- Who will be the owner-of-record for the site?
- Can you prevent your business partners from running off with your work?
- What is the form of the organization? (corporation, LLC, partnership, etc)
- How will it be documented that you are a partner?
- What is the work background of all the partners? How does each one's experience directly benefit the partnership?
- How much work is everyone else expected to do?
If you haven't answered all of these questions, don't do a shred of work until you can. If you go asking these questions and there's any hesitation by your partners, RUN LIKE HELL. Leave it alone.