With Ayu's decreasing sales and constant controversies lately, people over here seen to be afraid she will be forgotten or something like that... I believe someone with her impact on the music industry won't stop being a influential artist even if she goes through some lows from times to times.
One thing that IMO shows her influence on the industry is seeing japanese musicians, either professional or amateurs covering Ayu and making different versions of her songs... I think it would be interesting if we trade some of the japanese Ayu covers we can find on the net... Not karaoke singers or western fans, but people putting actual musical effort on it.
Those are some I really liked: