This is part of an email Amazon sent out to some sellers:
Amazon is turning 20 years old, and we’re planning a massive, global event to celebrate this momentous occasion! The event is planned for July, and will take place no later than July 20, 2015... We are looking for Lightning Deals, which are limited-time deals where customers can get discounts of 20% or more on specific items (based on the site price from the previous day and the average price for the previous 90 days)