There was a Disney Park Pack subscription that featured three pins per month earlier this year. It started in May of 2014 (see this
Parks Blog posting) and ran through September 2016 (or thereabout). Since then, they've had a monthly Tsum Tsum, ornament, and
coin subscription box (Tsum Tsums have also finished).
For the pin pack, each box included three pins. Two were available in parks (at some point after debuting in the box) and the third was a limited edition pin (usually with multiple variants) that was exclusive to the box. It was a pretty pricey, especially for something that you didn't know if you'd like the pins you were getting.