My cats do this, it's a love sign!
The glands on the sides of their mouths secrete their own special scent. WHen they rub on your or on furniture, what they are saying is, "YOU ARE MINE!". A great compliment from your kitty!
Some cats secrete more than others. My little KC rubs and drools so much when she shakes her head after a head-butt, she flings drool across the room.
My newest baby, Hamtaro, cannot get ENOUGH of rubbing his sweet little head everywhere. ESPECIALLY on my face at night. In the past week since I've adopted him, he has been on my face rubbing every single night, well into the wee hours. Quite a compliment and a sign of love.