Most people sign up for Amazon Prime for the same-day delivery perks, but the subscription quietly comes with a range of other benefits that many members never use. One X user, Lily, has gone viral for laying out exactly what subscribers are missing, arguing that members aren't overpaying for Prime, they're simply 'underusing' it. "Amazon is quietly hoping you never open the "Prime Benefits" tab," she posted. "I opened it. You're paying $139/year for what looks like a shipping subscription.