said by famines :
What is the cost to, say Bell, for a user to upload than to download? I've often heard that it's more costly for ISPs when their users are uploading. So around what is the cost differential? Is there a ratio, like 3:1?
That's almost certainly not true. Fibre connections (what your ISP uses upstream) are billed to the 95th percentile of whichever is higher (of downstream/upstream). Seeing as most users download more than they upload, a residential ISP will typically have far high downstream usage. Any single user uploading wont make a huge difference on overall traffic volume, keeping downstream the speed that billing is computed off of. As a result to an ISP you uploading is effectively free.