What I have been doing with the sites I have been creating is simple, link them all to a link on my domain. Example:
www.mydomain.com/keyword-one
www.mydomain.com/keyword-two
all link to
www.mydomain.com/fpa.html
so that way i can change my sponsors ad on a daily and if I ever have to change the link codes I won't have to change but one link.
I am pretty sure that there is an easier way but this makes sense to me.