President Donald Trump on Sunday continued to attack former FBI Director James Comey with a series of tweets aimed at undercutting the credibility of his upcoming book, "A Higher Loyalty."

Among other things, Trump called Comey a "slimeball" who should go to "jail" and who wrote "FAKE" memos aimed at smeared the president.

However, the president's tweets also had the unintended consequence of promoting Comey's book, which has already rocketed up the charts on Amazon's bestseller list despite the fact that it doesn't officially release until Tuesday.

Many Twitter users noted the irony of Trump helping his former FBI director sell more books -- check out some of the reactions below.