the credit card line is based off the standard 2.9% + $0.30 fee most major processors charge.
the bitcoin line is based on current mempool rates. the horizontal position of the bitcoin line will change as mempool fees go up or down, but the curve of the line will likely remain the same over time.
the vertical position of the lightning line will also change over time, but the line should remain flat, always enabling opportunities for making small value payments.
the lightning fee market is still evolving, and imo it hasn’t fully played out yet.
folks like @zerofeerouting could push other nodes to lower their routing fees to compete for a more central location on the network graph, while it’s also possible that fee rates rise over time to compensate node operators more for their liquidity.
basically none, because existing financial rails don’t support small payments.
imo the more interesting question is how many payments will be under $1 on lightning? what new use cases can we unlock that were never before possible?
look at how many new use cases the internet has unlocked when the transaction costs for moving information dropped to zero.
all the tiny transactions we make every single day (posting on twitter, instagram, googling things, reading blogs, etc…) were simply never feasible prior to the internet. but of course, these tiny transactions have spawned the biggest companies in the world.
on the payments side, we’ve got lots of emerging examples already (stacker news, fountain, mash, etc…) and there are lots more on the way. how many of the tips sent on v4v apps are under $1? probably most of them.
and when users can pay directly with their nodes or wallets, seamlessly moving sats anywhere on the internet, i suspect we’ll see a ton of new use cases that were always useful but simply never possible before.
another interesting aspect in this is that LN may not only capture small payments but also payments by small shops, niche industries (like adult entertainment) and all kinds of cross-boarder payments. That's because all these businesses are often excluded from tradfi payment rails because nobody wants to be an acquirer for them because they are too risky or too small. Even if LN had fees that are not too far away from Visa & Co., it still has the advantage of being entirely debit based, so no need to check any credit-worthiness or bank account, so the cost of processing payments of "riskier" industries is not higher than usual in LN
I'm guessing even if you factored it in, it wouldn't change the story too much, since on chain fees are pretty low, and you're unlikely to need to open or close channels too often
true, i suspect a lot of new bitcoiners in the coming years will have their very first interactions with bitcoin via lightning too… the concept of a base blockchain might not even matter to them