PurposeThis study aims to explore the direct and indirect effects of sales opportunism and sales conflict as well as of non-economic and economic satisfaction in business-to-business (B2B) sales relationships. This understanding offers B2B buyers enhanced knowledge of sales business expectations towards sustainable business relationships in the future.Design/methodology/approachThrough self-administered questionnaires, data were obtained from 237 sales or marketing managers/directors of small- and medium-sized companies across industries in Spain, who were randomly contacted via LinkedIn. The multivariate analysis of measurement and structural models was based on IBM SPSS Amos 27.FindingsThe study confirms that sales opportunism positively affects sales conflict. Moreover, sales opportunism is negatively associated with non-economic sales satisfaction, whereas non-economic sales satisfaction is positively associated with economic sales satisfaction. Consequently, if all associates are pleased with the relationship and the gains it can provide, a long-standing orientation can be achieved.Research limitations/implicationsThe study expands existing theory on seller–buyer relationships in a B2B context. It contextualises direct and indirect relationships between two antecedents (sales opportunism and sales conflict) and two postcedents (economic sales satisfaction and non-economic sales satisfaction) in sales business–buyer settings.Practical implicationsThe study guides buyers in B2B relationships towards an improved understanding of how sales businesses perceive opportunism and conflict (as negative precursors) to impact non-economic satisfaction and how it can influence economic satisfaction.Originality/valueMost studies explore B2B relationship building from the perspective of the buyer, thereby creating a shortfall in developing an understanding of all partner expectations in B2B relational intent. Moreover, the measurement of satisfaction as a multidimensional construct secured the integration of non-economic satisfaction and economic satisfaction within a single model allowing the constructs measured in this study to be holistically assessed.