This research investigates the impact of online reviews on consumer purchase decisions through sentiment analysis, focusing on the Indian e-commerce market, specifically Amazon India. The primary objective of the study was to analyze how different sentiments in consumer reviews (positive, negative, and neutral) influence purchasing behavior across various product categories, including electronics, clothing, and home appliances. The study employed sentiment analysis using the VADER (Valence Aware Dictionary and sEntiment Reasoner) tool to classify reviews and examine their correlation with units sold. Data was collected from 1,000 reviews, with a sample distribution of 500 positive, 300 negative, and 200 neutral reviews, across the selected product categories. The analysis found that positive reviews strongly correlated with higher sales, while negative reviews had a detrimental effect on purchase likelihood. Products with higher sentiment scores, particularly in electronics, saw the most significant sales increase. The research also indicated that products with higher review ratings (4 and 5 stars) had lower return rates and greater purchase frequencies. These findings highlight the crucial role that sentiment in online reviews plays in shaping consumer purchasing decisions, offering valuable insights for businesses aiming to enhance their online presence and optimize consumer engagement. The study emphasizes the importance of managing online reviews to boost sales and reduce product returns.