Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Amazon's outstanding service

The movie is great but what really impressed me was Amazon's customer service. When I rented the movie on Instant Video, it was extremely slow to load, if it loaded at all, and it was very frustrating to pause it and try to resume at a later time. Without me even contacting Amazon, they recognized the problem I was having and refunded my money. I am very impressed with them and this is the type of customer service that keeps me renewing my Prime membership year after year.