Yes, nothing of commercial gain at all, and not even a hit counter - on any of my sites, not just the one in question.
The reason for it been in my signature is that the tutorials were written basically to answer a great many of the PIC related questions on here - and I got tired of continually retyping the answers.
As for actual 'commercial' links in posts or signatures, I only allow them for proven valuable members - anyone posting here just for advertising purposes is deleted and banned.