Based on a survey of 145 tomato farmers and interviews with supermarket chains, NGOs, wholesalers, and farmer organizations in 2004, this paper examines the determinants and effects of farmers' participation in supermarket channels, with and without assistance from NGOs in "business linkage" programs. It finds that absent that assistance, the farmers that work with supermarket chains tend to be the "upper tier" of small farmers, better capitalized with various assets. The smaller and less-capitalized farmers that work with supermarkets tend to do so in association with NGO assistance. Despite higher input expenditures and entry requirements, farmers in the supermarket chain earn more. The paper discusses the issue of whether this development program approach is sustainable and can be upscaled, and wrestles with the tradeoff of helping poor farmers gain access to dynamic markets, of making it affordable at a larger scale by national governments with tight budgets, and at the same time field programs that are market-sustainable and market-responsive.