Purpose - The purpose of this paper is to explore the relationship between the actual usage of online methods for collaboration with customers and firms' innovation performance. Drawing on theories of knowledge flows and knowledge creation, this study analyses the results of customer collaboration in the online mode in comparison to the offline mode. Design/methodology/approach - The data for the econometric analysis comes from managers of 102 so-called "gazelles", knowledge-intensive service firms that were characterized by exceptionally stable growth rates in Sweden during 2010 and 2011. Findings - This study confirms the significance of information and communication technology (ICT)-supported collaboration with customers for a firm's innovation performance. Interacting with customers using online methods has a positive effect on companies' innovation output. Besides, knowledge-intensive service companies demonstrate more extensive though less intensive use of online channels for collaborating with customers compared to offline methods. Research limitations/implications - The data for this study has typical limitations resulting from the collection method of web-surveying. Future research should refine the findings of this study using various measures of firms' innovation performance. Practical implications - Firms should be more receptive towards online methods of collaboration with customers because using such strategy can increase their probability to introduce service innovations. The insights from this study are especially valuable for companies in knowledge-intensive service industries because the sample consist of companies that can be regarded as successful cases. Originality/value - This study is one of the first that addresses the issue of the impact of collaborative technologies on innovation performance. The sample of steady-growing gazelle companies adds value to the results.