Unity has launched a special promotion for the month of June 2018. You could get up to $311 in free assets.*
How does it work? Well its easy, all you have to do is go to https://assetstore.unity.com/g/june-promo-activation
Activate the promotion with your login email, once that is done you will have to spend between $50 and $250 in the Unity Asset Store during the month of June 2018, and get up to five free assets, worth $311 in value.
*Terms and conditions do apply so make sure you read them before activating the promotion.