I Received this offer through the Spotify app. I understand it may have been around for some time.
Get 50% back on Premium.
Use your QuicksilverŽ card and get 50% back as a statement credit on your monthly Spotify Premium subscription, now through April 2018.
https://www.spotify.com/us/capitalone/All plans are eligible.
Putting into perspective.
Family plan which can be shared with up to 5 devices is
$14.99 a month +Tax
($15 x 9 months = $135 - 50% = $67.50 +Tax.)