Every time you craft a set of Dota 2 game cards, you get a Dota 2 badge.
What are Dota 2 Steam badges?
Dota 2 Steam profile badges help you show to the rest of the world the kind of Dota 2 role you prefer. It also gives people an idea on the amount of time and money you have invested in the most popular game in the world.
Here are the different badges for Dota 2:
Support - Level 1 - Craft a badge.
Disabler - Level 2 - Craft a badge twice.
Jungler - Level 3 - Craft a badge thrice.
Initiator - Level 4 - Craft a badge four times.
Ganker - Level 5 - Craft a badge five times.
Hard Carry - (Craft a badge using all 8 Foil Cards)
The badge will be displayed on your personal Steam profile.
During Dota 2 badge crafting you'll receive random rewards from a set of Dota2 related items.
Stuff you can get:
Dota 2 background for Steam profiles