But following their success securing a $5 billion (GBP2.8 billion) aid budget at the G8 summit in the same month, Bono is thrilled by the outcome of the campaign.
He says, "There were a few of us worried about it. Geldof gave up his life for a year working on this stuff. No sleep and a lot of grief. Some balls were going to be dropped. Most went in the back of the net.
"Personally yes, I think it was a mistake not to have more African artists.
"Bob was being protective of the ratings because the ratings, he felt, would in the end be the thing that protected Africa.
"I wasn't so clear-cut, though. But it was Bob's show. Many African artists performed in Jo'burg that day.
"Most of the cameras chose not to cover the concert there which maybe proves Bob's point."