[2006] Does Ayumi time her releases with the products she endorses?

[Yukitora]

^ I don't really think so, Ayu really doesn't need any tie-in's with huge dramas or movies to get good sales. You'll see one-time hits in singles which is pretty much 90% due to the popularity of the drama.

Ayu does't need her tie-ins to boost her short-term sales, I think she does them to get her image around and solidly too. A tv-drama tie-in doesn't really do this, which is probably why she doesn't do them very much.