Waiting an average of two minutes for a transaction confirmation is a long time when there is a line of people at a checkout counter. This is particularly true when compared to nearly instant Visa/Mastercard confirmations.
Monero confirmations are 5x faster than Bitcoin on average. How do some retail merchants accept Bitcoin without waiting for a transaction confirmation (I have been to a bar for example and paid with Bitcoin without being required to wait for a block confirmation)?
Can retail merchants accepting Monero use the same method(s) that these Bitcoin retail merchants use to safely accept transactions without waiting for block confirmation?
Is scanning the mempool for transactions that have not yet been confirmed easier of more difficult for Monero compared to Bitcoin? If a Monero payment processor is used and is a victim of a double spend (after accepting a 0 conf transaction at a coffee shop) will the loss be eaten by the payment processor or the coffee shop?