Although Apple is yet to provide official confirmation, developers are finding that they are now being allocated 100 promo codes per version of their apps. Until today, the limit was 50.
Developers use promo codes to distribute prerelease versions to review as well as offering giveaways to users for promotions.
In the past, it has been a common complaint that the 50 code limit was too restrictive. 100 promo codes per version gives developers more flexibility in how their promote their apps.