I use CTR as measurement. I try new placements or different formats to see if I can increase it.
However comparing it to others does not help you at all.
A Forum that gets a 1.5% CTR with 500k uniques is doing good.
Comparing it to a blog with a 15% CTR and 11k Visitors per month does not help at all. It is like comparing apples with oranges.
Even a different niche means different CTR.