If I ordered a bunch of inflated helium balloons, should I get paid for the shipping?
Lets say I ordered balloons with a total volume of 1000L.
The lifting force of helium is 1 gram per litre. So the weight would be negative 1kg.
I’m ordering them from America to where I live, the Czech republic. It’s shipped by a plane and it’s priced according to it’s weight. 1kg costs roughly $38. Should I get paid $38, then?
No, because volume is as much a limiting factor on transportation as weight is.
The balloons (and their helium) still have weight; it’s only that the air around them is so much heavier. (A real eureka moment when you understand that!)
The company can just weigh your package in a vaccuum. Or, easier, simply calculate the mass and convert that to weight.
Or, even easier than that, charge you based on volume; I’m sure, somewhere, somebody has written regulations for large, lightweight items and how much to charge for them.
If nothing else, there’s always the ‘annoying git’ fee.
No allowance for the balloon material? Or the packaging?
More so, in fact. The Royal Mail here in the UK changed their prices fairly recently to reflect this. It now costs far more to send a light but bulky package weighing, say, 50g than it does to send a thin heavy letter weighing 100g.
In fact in their most recent price revision, the first weight step for parcels within the UK is “up to 1kg”. So it doesn’t matter if you have a helium balloon in your box or a couple of pounds of rocks. The price will be the same.
Weight is more of a factor in airmail, but again they have made the first weight step much bigger - up to 250 grams, rather than the previous small increments.
Exactly. The OP mentioned a volume of 1000 liters. That’s roughly equivalent to a box 6 feet by 2 feet by 3 feet, which is enormous in shipping terms.
Order a fully inflated Airship and see what that costs. 
Shipping is based on both weight and volume. For example, if you ship a box UPS and the volume (HxWxL in inches) is greater then 5184, you divide by 166 to come up with the dimensional weight. If dim weight is greater then actual weight, that’s the weight they consider it to be.
Did people get paid to ride in the Hindenburg?
Well, yeah, they paid with their lives.
Only the crew. And the migrant workers being smuggled in the cargo hold.
Is airmail still a separate level of service there?
Shipping is only part of the cost to get your stuff to you. Several people handle your package who need to be paid for their time and effort.
Also, if the package is so light it floats on it’s own, it would take someone to handle it all the way from origin to destination. 
Nevertheless, the balloons still provide some lift so they’d save on the fuel. Of course the pilots and workers still get paid, but I’d say the cost of the fuel plays a major part in the price, doesn’t it? And as for the airship, perhaps they could send it by itself with a built-in compass and remote control.
Good luck packing balloons in such a way that the box or container holding them is lighter than air. Your package will be of low weight, but no way does it yield meaningful (or even measurable) fuel savings as compared to leaving it behind.
Meanwhile, your bulky package is taking up space that could be used to transport a bunch of other packages - IOW, it’s causing the airline to forgo significant revenue. Expect to pay a good price for hogging that space.
And that’s true and it IS taken into consideration. Why do you think it’s not?
When we ship stuff, we box it up, throw it on the scale and quote you based on that weight. They box up the balloons, put the box on the scale and quote you based on the weight. The balloons are pushing against the top of the box making the package weigh less, which means your shipment will (theoretically) cost less. No, it’s not going to have a negative weight (the package isn’t going to float), but it will, technically, weight less then if it was filled with uninflated balloons. And again, you’ll be charged based on whatever the scale says.
Of course, in reality, a few balloons is going to create such a small amount a lift it’s not really going to tip the scales in your favor on this one. If an empty box weighs 5.6 pounds, filling it with helium balloons probably isn’t going to push it below the 5 pound mark. But if it did…
Like others have mentioned the shipper will charge you based on dimensional size. Also transportation of gases is highly regulated in the US. Inflated Balloons wouldn’t be allowed through customs. Balloons are not an approved container for transportation of gasses, as much sense as that makes. I wonder is if the DOT can impound little Suzy’s balloon.
When I read the price list for freight it is .
- price is the price by weight, or price by volume, which ever is GREATER
- Weight prices - (insert chart or formula)
- Volume prices -(insert chart or formula)
But I do get that Post Office services generally charge only by weight, up to a certain size. (not many balloons in that size.)
By airmail I meant “international”, as opposed to domestic mail within the UK. (I’m sure some domestic mail is carried by air, but you don’t pay any extra whether you’re posting a letter to the next street or to somewhere in the Shetland islands or Northern Ireland, say.
There is a cheaper “surface mail” rate for international mail, which is not actually that much cheaper and can supposedly take several weeks. In my experience, though, mail sent as “surface mail” still gets sent by air for the most part, anyway, just not as priority.
The OP never said anything about a box. He just said he ordered the balloons.
So I suggest: tie the balloons onto the wings and tail of the plane. That way, the plane is lighter, which saves fuel. Therefore, the OP deserves to both get free shipping, and even to get paid an AL Gore carbon credit for saving fuel.
See?
It’s simple—everybody profits! 
Not only does the airline save money, but the planet earth and all of humanity get to live longer, because global warming is being delayed.
1/ If you don’t make a payment in order to have the carrier ship the balloons for you, they don’t profit from you, which means they have no interest in your business. They aren’t there to break even, yanno.
2/ You might say that you are saving the carrier something by providing them with extra bouyancy ie that is effectively your “payment”. If it actually benefitted the carrier to use bouyancy balloons, why don’t they do that already?
Yes, I know this is a joke OP.