Dude, go to the bottom of any hub - yours, or mine, Hell, try it on one of mine, and you'll see.. . . .all you have to do is go to the bottom, hit "share" and then "link to this," and there it is, your referral tracker in my hub, or anyone else's hub.
Hubpages would NOT have made it like that if it were not only allowed, but encouraged.
The tritrain comment above is COMPLETELY WRONG!