Do you do job-based consultation? Say one has a project/website, and that person has some marketing goals in mind, can you quote a price instead? Also, any guarantee on effectiveness?
For example if your project is to take an iOS app from 100 users to 1,000,000. That I wouldn't take on as a project, that's what someone should take on as a career/job more than a contract. 100 users to 10,000 is something I would consider freelance/contract size.
Marketers on Demand was setup as a test of the 7 Day Startup framework and to run an idea validation thought. Not really for full on projects.