July 28 through August 4
If you’re a new player who logs into Heroes of the Storm from now until August 4, you’ll earn a seven day Stimpack bonus for your troubles. In essence, it’s an XP boost, which is augmented on a bonus for having a friend in your party.
In order to meet the requirements you have to have never played before on an account, and since different regional servers basically count as clean slates, you’ll get a bonus for jumping into another region as well. It isn’t a huge bonus as a seven day Stimpack costs $3.99 in the US, but it’s something.
Free Stimpack for New Players [Battle.net]