At least in the US, I think satisfying the 'purposes' requirement for non-profit status would be difficult. Just providing a free service isn't enough. Here's the IRS brief description:
"The exempt purposes set forth in section 501(c)(3) are charitable, religious, educational, scientific, literary, testing for public safety, fostering national or international amateur sports competition, and preventing cruelty to children or animals.
You seem to confusing non-profit status with charitable (501c3) status; a charity is a specific subtype of tax-exempt nonprofit (most notably different from most other nonprofits in that, in addition to the organization being tax-exempt, contributions to the organization are tax-deductible for the donors.)
You can file as a not-for-profit social purposes organization (to incorporate at the state level) without electing to take on IRS non-profit status -- you just need to pay taxes still.
Welcome to my new religion... All user content welcome! Seriously though, it does not have to be non-profit. It can be for-profit. Just as long as the cause is served.
"The exempt purposes set forth in section 501(c)(3) are charitable, religious, educational, scientific, literary, testing for public safety, fostering national or international amateur sports competition, and preventing cruelty to children or animals.
source: http://www.irs.gov/Charities-&-Non-Profits/Charitable-Organi...
UPDATE: I confused non-profit and charitable organizations. Disregard.