I have to agree with Ty! Its really not possible to determine what is "good" in a general sense. The key is to track and know your metrics. For example if I can get a media buy to bring in $1.50 to $2.00 for every dollar I spend in the real estate investor niche I am doing good.

Every market is different and like Ty said every form of advertising is different.

No holy grail answer here!

Bill