Shaun King received backlash Saturday after sending a promotional email that acknowledged Chadwick Boseman's recent death.

"I hope that you are hanging in there," the message began. "Yesterday I sent an email checking in on everybody — and just a few hours later we learned of the death of Chadwick Boseman. Life is so very fragile. Tomorrow is not promised."

In the next paragraph, King begins promoting his new book, Make Change: How to Fight Injustice, Dismantle Systemic Oppression, and Own Our Future. The activist/author explains his intentions for the book and how readers can benefit from it, before directing recipients to online stores to purchase the book.

Screenshots of the email quickly surfaced online, prompting many Twitter users to accuse King of exploiting tragedy.

"Shaun King is using the death of Chadwick Boseman to sell his book and it is GROTESQUE," Rewire.News editor Imani Gandy tweeted. "What is wrong with him? What is wrong with YOU THAT YOU KEEP SUPPORTING HIM?"

King responded to the allegations Saturday evening, insisting he does "not make a penny off of sales for my book."

"I had a mass email pre-scheduled to go out this morning about my book," he tweeted. "I updated the email to also mention the death of Chadwick. And I don’t regret it. At all. There’s that."

Boseman died of colon cancer on Friday night. His last tweet posted on his Twitter account is now the most-liked post in Twitter history.