Questions about heroin and balloons

[sc2005]

This may seem like a strange question, but I watched Pulp Fiction recently and Eric Stoltz's character (the heroin dealer) tells Travolta he's "out of balloons, is a baggie okay?" What's the deal with these balloons? What are the advantages of a balloon over a baggie? Are these special ballons or just party ones? Is heroin sold in balloons more pure or less pure, generally (I read an article that said it was typically less pure). Some pictures I saw on google made it seem like balloons were used for large quantity purchases. Is this true? Also, why don't people use balloons for cocaine?

Just Curious!

PS: I've heard they're used because you can swallow them/shove them up you know where. Come on! That can't be right! These damn things break easily, don't they!? Baggies would be MUCH better!