It's important to stress the usefulness of monthly donations, as opposed to single donations, even large ones. Monthly donations let organizations like the ACLU and the EFF plan for the future based on a reliable source of income, instead of individual donations which can be peaky.
What are the laws governing endowments? Could an organization fund itself indefinitely based on interest on an endowment assembled from millions of small one-time donations, or are there taxes or other rules that would eat away the endowment?
