Examines the combinations available to purchasers regarding the selection of suppliers (sources), e.g. the use of a single or two or more (multiple) sources. Considers the justification of either method in the context of reducing the uncertainty (risk) of a particular purchase. Illustrates the marketers view of sourcing and the differing sales tactics employed according to the suppliers′ preferences. Concludes that purchasers should examine uncertainty buying‐selling situations (UBSS) objectively with regard to their own organizations′ need criteria, e.g. cost and timeliness, this determining the relevant sourcing policy.