Two months prior to Back To The Egg's release, Wings issued a standalone single, Goodnight Tonight/Daytime Nighttime Suffering in March 1979. It became a top five transatlantic hit, and became Wings' third best-selling single.
The a-side had been recorded during the London Town sessions but received further overdubs while Wings were recording Back To The Egg. Daytime Nighttime Suffering, which was originally considered for the a-side, was recorded at Replica Studio during the mixing of Back To The Egg. McCartney challenged the members of Wings to each write a song over a weekend, with the best to be recorded and possibly used on the album.
Another single, Old Siam, Sir/Spin It On, followed in the UK in June. In the US, Getting Closer/Spin It On became a single; both releases were moderate hits, reaching numbers 35 and 20 in their respective charts.
Back To The Egg was released in the UK on 8 June 1979; it reached number four in the charts, spending a total of just eight weeks on the countdown – the shortest run of any Wings album.
Three days later it was issued in the US, peaking at number eight. Sales of the album were initially strong, but lacked the momentum to become a chart-topper.
I saw a thing on the telly the other night. It said that there are three million copies of Back To The Egg waiting around in a warehouse, which sounds as if it is the world's greatest flop. But for any other group to sell a million, which the album has, it is a major success. It is a good album; it's the band's first album. Those copies that they didn't sell were mainly because the record company produced too many. They just thought that it was going to sell in huger quantities and they got stuck with them, which I think is a daft idea anyway. I think they should wait until somebody orders them, and then print them up.
At 12.30pm on 11 June 1979 McCartney held a press conference at EMI's Studio Two. The studio was decorated to look like a giant frying pan, with the walls covered with black curtains, and tables adorned with yellow parasols to represent egg yolks.
The album was played to invited guests and reporters. Also at the event was the first screening of the Rockestra film, though only 15 minutes were shown. The film crew were presented with an engraved egg cup and spoon by the McCartneys.
Two collectible promotional items were created for Back To The Egg. A box set contained an egg-shaped badge, key ring, booklet, sticker, postcard, five smaller cards and a t-shirt, as well as a copy of the album.
The more valuable, however, was a picture disc pressed by EMI featuring the cover artwork on both sides. Limited to just 100 copies, it became highly sought after, though counterfeit versions are known to exist.
In-store displays and other promotional items including egg-shaped jigsaw puzzles were also manufactured at the time of the album's release.
On 10 August 1979, Getting Closer/Baby's Request was released as a single in the UK, but rose no higher in the charts than number 60. Three days later a US single, Arrow Through Me/Old Siam, Sir, followed, and peaked at number 29.
Back To The Egg was first issued on compact disc in July 1989, and had three bonus tracks: Daytime Nighttime Suffering, Wonderful Christmastime and its original b-side Rudolph The Red-Nosed Reggae. The album was remastered and reissued in 1993 with the same bonus tracks.
Wings' final tour took place in November and December 1979 across Britain. Performing in theatres rather than stadiums, the group ended the tour in Glasgow on 17 December.
Their final performance, however, was at London's Hammersmith Odeon on 29 December. Kurt Waldheim, the then UN Secretary General, approached McCartney to ask if Wings would give a charity concert for the victims of war-torn Cambodia (then Kampuchea). The result was a series of events, Concerts For The People Of Kampuchea, which featured The Who, Queen and The Clash as other headliners.
The final concert was also Wings' last. A live version of Rockestra Theme was performed with many of the original performers, including Wings, John Paul Jones, John Bonham, Robert Plant, Rockpile, James Honeyman-Scott and Pete Townshend. Most of the performers wore silver suits for this performance.
The audio recording was released as an EP and on the 1981 live album Concerts For The People Of Kampuchea, which also included Wings' performances of Got To Get You Into My Life, Every Night, Coming Up, Lucille and Let It Be.