Cascading Ad-units in DFP Small Business

Question

I have 2 ad units:

1. Homepage banner
2. ROS Banner (run of site)

Basically, I want to find a way to server ROS Banner when Homepage Banner doesn't have anything to serve so the impressions are wasted.

I found this, but was wondering if anyone knew a better way:

http://gam.ingraye.com/cascade/

Answer 1

回答，没有别的办法。