In my opinion, you don't need to use a lot.
Excellent advice with regard to using it on chicken. I also like to use it on whole beer can chicken and sprinkle some inside the body cavity.
It's really an excellent all-around rub. It has a well balanced flavor. I've even used it on brisket and it tasted awesome.
I do think that fruit woods are more compatible with Plowboys Yardbird. Stronger flavors like hickory kind of begin to overpower the rub.
Anyway - enjoy it! Cheers!