Hershey's has successfully blocked many of the British original versions of Cadbury's chocolate and other confectionery being imported to the US. They have the rights to sell it here as they manufacture it under licence here. Thing is, they make it (mainly the chocolate part) to their own recipe which is sub-standard and taste like crap.
Hershey's chocolate itself is a sickly over sweet abomination to my palate. It taste like cheap, imitation chocolate that you can buy in the penny kids (or a few pennies now) counter in the UK.
Full story: BBC News - Cadbury in the US: Fans stockpile sweets