Heart Shaped Box was my first Joe Hill read. I don't know for sure if his identity was widely known then, but I do know I got my copy through Book of the Month, and that I bought it solely because I thought it sounded good. No where in the description of the book was it mentioned who he was.
I know there are differing opinions on whether Joe writes like his father. But for me, the tone was immediately recognizable. Not to diminish his talent in any way, to me it was just a case of he learned from the master. But it was similar enough to me to take the jacket down and give the author picture a good once over. Then it was obvious to me. But I really had no idea beforehand.
Can't say it bothered me though. I got a chuckle out of it and a thrill knowing there was another King out there to read.