Online reviews and influencer-centred social media conversations jointly shape product understanding in digital markets, yet they are still often studied as separate streams. This gap is especially relevant in the beauty sector, where product evaluation depends on subjective experience, perceived efficacy, tolerability, routine fit, and trust in peer-generated accounts. This study develops a cross-platform comparison of Amazon reviews and YouTube comments related to three active skincare products from the same brand, to examine whether the emotional profiles emerging from marketplace reviews differ from those found in influencer-centred comment spaces, and whether YouTube comments reveal needs, doubts, and advice-seeking signals that remain less visible in marketplace environments. The analysis is based on a replicable pipeline that combines data collection, filtering, text preparation, and transformer-based emotion detection using RoBERTa GoEmotions. The findings show that Amazon and YouTube do not produce equivalent emotional profiles. Across the three products, Amazon tends to concentrate emotional expression around admiration and approval, whereas YouTube comments display a broader and more fragmented emotional repertoire. The paper contributes theoretically by integrating review research and influencer ecosystems within a common comparative perspective, methodologically by proposing a transparent cross-platform workflow, and managerially by showing how YouTube-centred social listening can support the detection of consumer concerns that remain underrepresented in marketplace reviews.