Amazon just started a new promotion that gives new subscribers to Amazon Music Unlimited a free $10 credit to use towards the subscription cost. To receive the credit, click the “Add gift card or promotion code” button on the promotion’s page and enter the promo code AMAZONMUSIC. Then sign up for any of the Amazon Music Unlimited subscription options. After your 30-day free trial ends, you’ll have $10 worth of credit in your account that will be automatically applied to your subscription dues. If you’re a Prime member, the best bang for your buck option is the $79/yr plan. With the free $10 credit, that comes to just $5.75 per month, which is almost half what most other streaming music subscriptions cost.