well honestly it would be hard for this song to do as good as 1004 since 1004 was more public friendly all those downloads were from their fanbase, which of course got smaller after 2 years.
This albu was produced by Bang and the other album with horrible digitals sales is also produced by Bang, if you see a pattern here. Even among the fandom his music is a long it or hate it type of thing so I imgine it does worse with the public.
They are rebuilding their fanbase now, their physicals were pretty good. We have to wait until their next comeback to see.