The purpose of this study was to examine the impact of customers' perception of the usefulness of online reviews on brand attitude and brand image (case study: Digikala website). The research method was survey-based, adopting a quantitative approach and classified as applied research in terms of its objective. The statistical population consisted of individuals over 18 years old who had experienced online shopping from the Digikala website. To determine the sample size, Cochran's formula for infinite populations was employed, estimating a sample size of 384 individuals with a 95% confidence level, using convenience sampling. Data collection was conducted through a questionnaire developed based on prior research. The face and content validity of the questionnaire were confirmed by experts. The reliability of the questionnaire was assessed using Cronbach's alpha coefficient, which exceeded 0.7 for all variables of the study, as determined using SPSS software. Data analysis was performed using structural equation modeling (SEM) with the statistical software SPSS24 and Smart PLS2.

The findings revealed that product knowledge significantly affects the perception of the usefulness of online reviews; the perception of the usefulness of online reviews significantly impacts brand attitude and brand image (P-value<0.05). However, source credibility does not significantly influence the perceived usefulness of online reviews; social influence does not significantly affect the perceived usefulness of online reviews; and perceived brand trust does not significantly impact the perception of the usefulness of online reviews (P-value>0.05).