It's going to be some years before anyone comes within inches of IGFs record. They're at 8.4 million and at 526 on iTunes. Adele's at 7.9 million and is at 369 on iTunes.
IGF is the song that'll never die (especially for summer/parties) whereas RITD will sell based on Adele's name alone and it being her signature it. I think she'll end up surpassing them first before anyone else can.
trust me, if it was upto me i'd not have ANY song overtake that Holy I Gotta Feeling
but sooner or later soneone will, and i LOVE Blurred Lines enough to be happy for it, if it does overtake IGF eventually! which i do think there are strong chances of happening!
No, it's a wonderful well-done pop track, a classic from the 2000's I don't blame all the whole people who bought it, it was so awesome, I felt good on so many levels when I was listening to that song in 2009, it was everything, it can be repetitive yes, but you don't pay attention because all the production. Plus, the song is so well received because IT ACTUALLY IS a group song, I love it because of that, it shows how is really the Black Eyed Peas, they are a group and united they create a gem
. For Applause is just 
