The Internet offers companies many opportunities to implement new business models, called e(electronic)-business in short, and to reinforce their competitiveness in the market. It is currently suggested that business-to-business commerce, which is one of the dominant segments in e-business, is going to develop around e-marketplaces. However, the new millennium has witnessed the rise and fall of many "dot.com" firms and now both the companies and the investors are extremely cautious about the performance and effectiveness of the e-marketplaces. To get more benefit from this digital marketplace, suggests the use of fuzzy logic based on multi-criteria evaluation as a superior means of improving the efficiency of the decision making or the e-marketplace selection under uncertain conditions. This evaluation approach, in which both fuzzy analytic hierarchy process and fuzzy Delphi methodologies are employed, enables one to deal with the uncertainty and vagueness from subjective perception and the experiences of humans in a group decision process and ensures a more convincing and effective decision making. Also shows the application of the approach on a real life case.