Jack11111, the BBJ makes up ~20% of the total orders for the 747-8 Intercontinental (i.e. passenger version).
While the percentage numbers were no where near that high, there are quite a few "business jet" variations of the older 747s out there. Some were new build BBJs, including a couple very ornate 747s that went to middle east sheiks (things like gold plated bathroom fixtures, on-board operating rooms, and devices that always pointed towards Mecca). Many others were converted from airline service to business jets - there is a casino in Las Vegas that keeps a couple of executive 747SPs on hand to fly around the high rollers (I've seen them parked there when I've flown into Las Vegas). And of course there are the two Air Force One 747s.
IIRC, one A380 was sold as a business jet but never delivered...