Come on, this is sci.space.  An orbital billboard won't
do any permanent damage; in a few years it will reenter
and probably hit Los Angles anyway :-)

The boost to space commerce orbital advertising might
provide might speed the day it is possible for those with a 
yen for dark skies to get some really dark skies beyond
the dust producing the zodiacal light. 

Now, if they wanted to paint the CocaCola symbol on the
moon in lampblack, that would give me pause.  It would
be very difficult to reverse such a widespread application
of pigments.
