Yeh, first time I tried HP5+ it came two rolls bundled in a blister pack of 25 sheets of MGIV RC pearl.
Didn't care for the pearl finish paper but liked the film.
Ilford has also occasionally offered discounted 4-packs of FP4+ and Delta 3200, which prompted me to try both. Now I like both.
When I recently placed an order with JandC Photo they offered 5+1 deals on several types of film and similar deals on other products. So I ordered five rolls of Efke R100 and got the freebie roll. Great film, good deal, so I'll be ordering from JandC again.
Meanwhile Kodak seems to do little to promote their traditional b&w products. I don't recall ever seeing, say, a roll or two of Tri-X bundled with a pack of Polycontrast RC in a retail store.