Depending on personal preference, it is either an expression of joy, happiness or delight or an expression of sarcasm in response to a small gain/reward etc.
Joy.
"You got an A+ on your maths test!"
"Goody gumdrops!"
Sarcasm.
"For finding the cure for cancer, we give you this small keychain."
"Oh, Goody gumdrops"
1. Derived from seven characters of famous play The Crucible- all dead. A fantastic explanation for unusual happenings or an answer to any question.
2. A well known song that everyone enjoys hearing because it's beautiful and famous.
1. Guy- Did you see that unusual happening?
Other Guy- It probably had something to dowith Goody Putnam's babies.
Guy- I have a question.
Other Guy- Goody Putnam's babies.
Someone called this because they won't do stupid and immature crap like the majority of their peers.
If you drink and throw your guts up, you're allright
If you choose not to and have a good night's sleep or even sit up reading a book or having clean fun, you're a goody goody.