I'm skeptical (surprise.) Markets favour simpler solutions, and I'm betting that merchants will struggle to open LN channels for a long time - it's a very technical thing.

The purpose of LN is to save space on the main Stellar chain - if this thing is going to scale to millions of people, and if it is going to be affordable for people other than businesses to run validators, then the size of the database needs to be kept to a minimum. It doesn't answer your question, though.

One use cases I see it working for is micropayments. If I'm an advertiser that wants to pay a user on a per click/per second basis for viewing add. A payment channel works well here:

1. User opens up a new session in your amazing new Crave Browser (yes, Crave cereal, definitely not a rip-off of a Coinbase listed token.)
2. Crave opens a LN channel with you.
3. For every ad click/second of a video you watch, Crave sends you XLM.
4. You decide to click on 5 ads and watch 30 seconds of video and close your session.
5. LN channel closes and settles the amount with you for 5XLM or whatever.

From what I understand about the LN so far, this broadcasts 2 transactions to the Stellar Network instead of 35 transactions that it would take without.