Abstract This research examines the effects of extension mode (online to online vs. online to offline), web-brand concept (function oriented vs. experience oriented) and extension similarity (high vs. low) on consumer web-brand extension evaluations, attitude, perceived quality, and purchase intention of the extension brands. The analysis reveals two significant interaction effects: (1) the positive effect of brand extension similarity on consumer evaluations is stronger when the parent brand is function oriented compared to the experience-orientated ones; (2) the positive effect of brand extension similarity on consumer evaluations is more pronounced when the web-brands extend to offline markets rather than to online markets. Implications for marketing theory and practice are discussed.