Quote from: chubogo on October 13, 2016, 01:50:39 AM

Question is really can you pay or receive a fraction of a satoshi?

In off-chain systems, you can split the satoshi into as many pieces as you like.

For instance, if Coinbase wanted to, they could implement a system that would allow Coinbase users to pay other Coinbase users smaller increments than a Satoshi and it wouldn't require any changes to the current Bitcoin system at all.

Additionally, multiple off-chain systems could cooperate if they want to.

For instance, Coinbase and BitPay could have an agreement between them that they would allow their users to make payments using smaller increments than a Satoshi between the two systems. Coinbase and BitPay could then just add up all the small increments from all the users and use the Bitcoin blockchain to settle up the transfers when the sum of the amounts are greater than a Satoshi.

However, it is currently impossible to send amounts less than a satoshi on the bitcoin blockchain. Allowing that would require a change to the bitcoin protocol and software.

I'm not certain, but I think that the new Side Chain concept that SegWit is supposed to make possible might allow for amounts smaller than a satoshi?