A system, method, and computer program product for generating item recommendations based on sensor data captured by sensors on client machines. A server processes collected sensor data to estimate user physical activity based on sensor data patterns, and forms a user profile based on the estimated user physical activity. The server associates the user profile with relevant product or service recommendations, based on previous purchases by a user or by others matching the user profile. The user may make a purchase based on the displayed recommendations or forward the recommendations to others. The recommendations include discounts based on the user profile. Subsequent sensor data showing satisfaction with a purchased item serves as a testimonial to user satisfaction with the item. The sensor data may be collected from a user in an augmented or virtual reality system, and the recommendations may be displayed in such a system.