Spotify gift cards, like any other gift cards. And they are currently available in 3 different kinds of values for different countries: $ 10, $ 30 and $ 60. You can exchange these cards for the Spotify premium / unlimited subscription.
This is one of the best gifts you can give to any of the music lovers among family and friends. They will appreciate them very much if they are in online streaming services.
When you buy these Spotify gift cards, they come with the code you need to enter and thus exchange your gift card value on your Spotify account.