To help customers get quality feedback from the huge number of online reviews, online retailers attempt to generate evaluations from consumers of how helpful product reviews are. Drawing on signalling theory, this study proposes a comprehensive model to examine the influence of factors related to the reviewer (signaller), the review (signal) and the users (readers of the signal) on online review helpfulness via e‐commerce sites and apps. This study also includes the moderating role of product categories (goods/services) in the model. Data were collected from 466 Vietnamese respondents. Using a Smart Partial Lease Square 3.0, the outcomes indicate that online review information quality, online reviewer information credibility and two dimensions of receivers (e.g. users’ attitudes towards information and information task‐fit) all have a significant influence on online review helpfulness; however, users’ need for information has no impact on the helpfulness of online reviews. Interestingly, the product type (goods vs services) has a moderating effect between online review information quality/attitude towards information and online review helpfulness. This study contributes significantly to signalling theory and online review helpfulness by comprehensively incorporating three attributes that are paramount to online reviews: the review, the reviewer and the users. Additionally, the information is enriched by the investigation of the moderating effect of product categories (goods vs services) on the context of online review helpfulness.