It's an interesting thought-experiment, carried through in full by Damon Knight in "A Reasonable World". It's a book with a silly premise: An alien lifeform, telepathic and empathic, infects the world. Anyone who is violent to others (causes psychic pain) falls down dead. People become nice. very nice. or die.
One side effect, started by a con man hoping to make a fortune off of a cult, is the moneyless society. Now, a barter society works only to some extent, but how do you quantify in volume such indefinables as art, writing and architecture? How about medical services? The premise of the cult is that the ultimate moneyless society is based on
need and NOT
fair trade. Thus, a crippled individual needs an electric wheelchair or mobility device, but cannot produce
anything to barter for it at any reasonable price. They still get it. And whatever they can give back to society, they give.
A farmer will only need shoes once every six months or so from the shoemaker, but the shoemaker will need food every day. They still trade, but not ona 1:1 basis. It's more a "I'll scratch your back, you scratch mine... no matter how big the itch is" kind of thing.
BUT, since we're all human, all inherently a little selfish... it'll never work.
As an economic system, communism has its pitfalls, but I think it's as a political system where communism really stinks. Democracy allows for the turn-over of malfunctioning political units... Communism doesn't. Socialism does work, but the only examples of that are small, rich European countries... hell, Switzerland could be fascist and it'd
still work.
That said, Democracy has its pitfalls, and is too easy to abuse... but that's mostly because 90% of the voting population are
idiots who flip a coin for their vote, or who vote based on abtruse and abstract political loyalties. And people who get elected are often the people who WANT power... those are usually the most dangerous of all. In a Communist/Fascist system, they stay there, but at least in a Democracy, there's a chance of kicking them out.
I went to a state University that was full of Communists. Not your average "I'm a communist because it's cool" western student, but hardcore, indoctrinated-in-the-mountains, farmer's kids Communists. The kind who go out on the streets and throw rocks at everyone. It's depressing how intelligent they seem, yet how blindly they carry on in the face of intelligent debate. At least some of these kids, when they grow up, turn into useful members of our
capitalistic society. The kind who get into it as a fad just never graduate...

...because they're just plain dumb.