https://www.cnbc.com/2018/07/03/amazon-makes-prime-day-better-by-charging-sellers-more.html

Amazon has turned Prime Day into one of the biggest online shopping holidays. But for many sellers, it’s becoming more expensive to participate.

For the second year in a row, Amazon has increased the registration fee to run Prime Day Lightning Deals, which are limited-time promotions exclusively offered to Prime members. It now costs third-party merchants $750 to run each Lightning Deal, up from $500 last year, according to an invitation that was sent to sellers and viewed by CNBC. Amazon first introduced the fee for Prime Day last year, after not charging anything in 2015 and 2016.