I demoed [0] receiving one tenths of a cent's worth of bitcoin (0.00000010 BTC) instantly, and on Bitcoin's mainnet (not a test network).

I also demoed [1] purchasing swag from Blockstream's store [2] which is powered by their newly released Wordpress e-commerce plugin [3] that enables Lightning payments.

I did not screencapture the videos because Qubes dom0 does not come OOTB with screenrecording software, and I don't want to enable networking in dom0 to install software that does.

[0]https://twitter.com/notgrubles/status/955611467889422337

[1]https://twitter.com/notgrubles/status/954933507863863296

[2]https://store.blockstream.com/

[3]https://blockstream.com/2018/01/16/lightning-charge.html

It exists in its early stages, but it's terribly impractical, hence no exchange or end user is in a rush to adopt it. Its design is almost like someone took a hard look at Bitcoin and concluded "Gee, this is not cumbersome enough for people, we need to make transacting a worse and more confusing experience".

Here is a graph showing the number of lightning network payment channels on the bitcoin mainnet: https://p2sh.info/dashboard/db/lightning-network?orgId=1

Working implementations exist and are usable, but they are being very cautious before releasing to the general public.

it's not useful for speculating on the price of bitcoin so few people will use it

You can buy coffee https://twitter.com/alexbosworth/status/955870434230132736