I too always add sausage to my regular Thanksgiving stuffing. I do get a great crust but I don't think the sausage is the reason. I use Pepperidge Farms Herb stuffing and add all kinds of stuff. I saute celery (lots and lots of celery), onion or better still leeks, bell pepper in the butter called for on the directions. I add additional fresh herbs like the Simon and Garfunkle song (parsley, sage, rosemary and thyme) and even other herbs like summer savory and marjoram to the bread crumbs. Turkey stock and cooked breakfast sausage meat with more sage added. Mix it all together and stuff the bird. Any leftover gets put in a separate casserole dish and baked. If I can get my hands on them I will also add Chestnuts. The stuffing from the bird gets a wonderful crust on the little bit that is exposed at the cavity. The casserole one gets a lot more crust. Both on the top and where the stuffing comes in direct contact with the dish. I make sure to either butter or spray pam in the casserole dish.