[jd]

I think you're trying to do both business and charity at the same time, and that doesn't really work I think. If you run a great business and make lots of money (by providing even more value to customers) you can then put that into any pet projects you may have. It will even go much faster.

You can now commit to help 10% of all your customers for free, for now into the future, and charge a sensible rate to everybody else. Your business will do better and it will grow more quickly. The 10% portion you help for free will soon be much larger than your total customer base now.

[chmike]

This is the only viable model for free. The balance depends on the cost of free and the benefit of not free. The cost of free (or cheap) should include the cost of support of bad clients.