And what is the practical use of LN?
Cheap small transactions and fast confirmations! I've recently installed a LN-wallet, and I already made more transactions on LN than I made on Bitcoin in at least a year.It makes small payments possible again, such as sending 0.0001 BTC with 0.0000000202 BTC fee.
I'm okay with paying a high fee for a big transaction, but I'd love to be able to use Bitcoin for small transactions too. LN allows much more users to actually use it, as 7 transactions per second can't scale up.
So small fees. To one specific target. Cost of opening/closing such a channel?