ok first of all, people move around singles and albums for the sake of sales because every artist is on a label, and every label wants to maximize their profits. there's nothing cowardly about it, it's business.
there's always a
chance that people who already bought the ringtone/full song don't necessarily
need to buy the full single. i mean i really don't think ringtones/full song downloads help the sales of singles. "koi no tsubomi" sold a huge amount of digital downloads, but the single didn't sell anywhere close to the same.
however, i
can say that the commercial featuring the song is played almost every other commercial break. so the influence on casual fans has been high for awhile now. it's been airing for a rather long time.
we just have to hope that ayu's song is a hit with not only her fans, but with very casual listeners. and as she has two songs, it might fair equally. but it depends on whether or not she chooses to promote both i guess. day/green was mostly driven by the sales of days, not green. haha