CD Stoplight pen vs Sharpie Green Marker

I recently tried Sharpie green permanent marker($1.29) to paint the edges of some CDs my player had trouble reading and had very good results with it.What is the advantage of using $8 pen?
TRy a black permanent marker and compare.
sol322 gave good advice....supposedly the markers help prevent laser light dispersion....if you can hear a difference and like it go for it....tweaking if part of the fun of this hobby.
I used to use a green paint pen, but being lazy have gone to a black marker pen. All it needs is to stop some of the reflected light scatter. And black certainly will do as well as geeen for a red lazer. (for a 'blue' lazer do you need an orange marker? (8^Q... )
finger nail polish. Find a way to spin the cd, then gently touch with brush. Art supply stores have paint markers. These 2 ways are better than sharpie markers. Markers still allow light through.