Why do chocolate bunnies get thinner every year?

[Galago]

-snip-

[Zorgoth64]

I got a giant Reese's Egg the size of my fist and a one inch thick solid, crispy, chocolate bunny this year, I'm not disappointed.

[ChaosUnleash]

Didn't they say that eggs have been reduced in size by about 60% this year? My easter egg was smaller and nowhere near as thick aswell.