U2’s latest album, "No Line on the Horizon," has sold one million copies, but Bono is disappointed with how the group’s latest offering has performed.

The diminutive lead singer of the world’s greatest rock band feels that the album has had a tough time competing in the saccharine-laden pop-filled music landscape of today.

"We felt that the 'album' is almost an extinct species, and we [tried to] create a mood and feeling, and a beginning, middle and an end. And I suppose we've made a work that is a bit challenging for people who have grown up on a diet of pop stars," Bono told Britain’s The Guardian Newspaper.

In the same interview, the Edge went on to say that "No Line on the Horizon” was more of a slow burner that would be appreciated in time.

"There's a lot of records that make great first impressions. There might be one song that gets to be big on the radio, but they're not albums that people ... play a lot. This [isn't like] that, I gather from talking to people. Four months later, they're saying, 'I'm really getting into the album now,'" he said.

The band is currently on its 360 world tour and plays the final 2009 date on Wednesday night in Vancouver.