To get a free booster, you need to:
- Visit The Humble Store website and collect a stamp
- Head over to giveaway page, scroll down and claim Warframe Humble Booster
- Log in on Warframe website and enter the key on this page
This booster includes: Foxglove Syandana, 200,000 Credits, 3-Day Affinity Booster, 3-Day Resource Booster. Enjoy!