"Community Supported Agriculture consists of a community of individuals
who pledge support to a farm operation so that the farmland becomes, either
legally or spiritually, the community's farm, with the growers and consumers
providing mutual support and sharing the risks and benefits of food production.
Typically, members or "share-holders" of the farm or garden pledge in
advance to cover the anticipated costs of the farm operation and farmer's
salary. In return, they receive shares in the farm's bounty throughout the
growing season, as well as satisfaction gained from reconnecting to the land and
participating directly in food production. Members also share in the risks of
farming, including poor harvests due to unfavorable weather or pests. By direct
sales to community members, who have provided the farmer with working capital in
advance, growers receive better prices for their crops, gain some financial
security, and are relieved of much of the burden of marketing."
(from http://www.nal.usda.gov/afsic/pubs/csa/csa.shtml
)