Hershey's Empire Strikes Back Card Set (Hershey Foods, 1980)

Boba Fett (Reese's Peanut Butter Cups)

To promote THE EMPIRE STRIKES BACK in 1980, you could get a free, one-sided, 4x6" trading card on the bottom of the cardboard holder from 6-packs of Hershey's candy bars.  There were five in the set, and they were broken up over different products, including Krackle, Hershey's with Almonds, Rolo, Mr. Goodbar, Reese's Peanut Butter Cups, and also Crunchy Reese's (which I think they don't make anymore?).

You can tell that the two cards on Orange cardboard were from the two Reese's varieties, and I've tried to point out where the others were from, below.  It looks like that some cards were available on two different candy bars.

C-3PO and R2-D2 (regular Hershey's)

Chewbacca (Hershey's with Almonds; I don't think they use this color scheme any longer for this candy bar)

Darth Vader (Crunchy Reese's, but also available on Mr. Goodbar, with Yellow backing, and Whatchamacalit with White backing)

Luke On A Tauntaun (Rolo, but also available on Krackle, with Red backing)

I wish more food companies would do things like this today.  It's a simple and low-cost way to promote a product, and it always works on customers like me!