On 21 August 2017, several U2 fans in the United States received cryptic letters via postal mail teasing a new release from the band. The letters contained text mentioning Blake's "Songs of Innocence and of Experience", with a silhouette of Bono's son and the Edge's daughter from the album cover blocking out most of the text except for a few words, revealing the message, "Blackout ... It's ... clear ... who ... you are ... will ... appear ... U2.com". The bottom of the letters said "U2 will announce" but blacked out the release title and date. Many of the recipients of the letter were in the path of that day's solar eclipse. On 30 August, after posting a teaser online the day prior, the band unveiled a video on Facebook Live showing a live performance of the new song "The Blackout". The video was part of a strategy to energise U2's core fans on social media by reaching them with new music first. "The Blackout" video was viewed more than 2 million times in 24 hours and 11 million in over a week.