This research investigates how personalized communications enhance customer-company relationships, which ultimately produce favourable marketing outcomes. Two factors were manipulated in an online experiment: the perceived effort made by customers to obtain a personalized newsletter (high vs. low) and the level of relevance of the message (high vs. low). The results indicate that perceived effort positively affects calculative commitment (even more so for highly involved customers), while the level of relevance of the message increases affective commitment. In addition, the interaction between perceived effort and message relevance has significant effects on calculative and affective commitment. Finally, affective commitment partially mediates the relationships between relevance and both loyalty and word-of-mouth intentions. Managerial implications regarding the best usage of personalized communications are discussed. Copyright © 2013 ASAC. Published by John Wiley & Sons, Ltd.