But in the past year, some key announcements from major chocolate makers have heartened human rights watchers.

Last March, Cadbury announced that it would produce all of its Dairy Milk bars with fair trade chocolate. “That’s an iconic chocolate bar, and it means that you can walk into any store and buy a fair trade bar. You don’t have to go to a health food store,” says Fitch-Frankel. The bar was so well-received in England that Cadbury expanded its production to Australia, Canada, and New Zealand. (Hershey makes Cadbury's bars in the US.)

On the heels of that announcement, Nestle announced that it would go fair trade with its four-finger Kit Kat bar, but only in the UK.

And then Green and Black’s spoke up: The Cadbury subsidiary announced it would turn 100% of its offerings into fair trade products -- globally.

That leaves open the possibility that one major chocolate maker in the US will take advantage of “the sheer marketing potential" of having the first fair trade chocolate bar in American supermarket aisles, says Fitch-Frankel. "It would be a windfall."

“Shareholders should be angry because not making this bar is reducing the company's potential profitability,” she suggests, “especially in light of the fact that it’s cheap to go fair trade.”

Now the question is, which major brand will be first to bite?