[cgjaro]

Correct, best practices and doc says to wait for 6 confirmations. But in practice, very few people do this. For example you can send bitcoins to your Coinbase wallet and sell them without even waiting for 6 confirmations.

Let me explain to you why this is okay in practice. A merchant will in general send something to the customer (a seller would ship an item, Coinbase would send an ACH bank transfer, etc). But because sending the service or product to the customer takes time, this gives time to catch double spend attempts. So a merchant considers 1 confirmation as sufficient, and prepares the shipment right away, or initiates the ACH right away. But if in the next hour the 2nd-6th confirmations never come (eg. the 1st confirmation ends up in an orphaned block) then the merchant can cancel the shipment of the item, or cancel the pending ACH.

[eridius]

But that only works when the merchant's half of the transaction is cancelable/reversible. That would never work in, say, a retail store, because the merchant can't catch the guy an hour after he's walked off with that $2000 computer.

[cgjaro]

Merchants are ALREADY taking a risk with credit cards if, after walking away with a $2000 computer, the guy issues a fraudulent chargeback.

So if a merchant accepts the (non-negligible) risk of credit cards chargebacks, he will accept the (even smaller) risk of a Bitcoin double spend :)

[eridius]

Yes there's a risk, but it's a relatively small one. There's a chargeback arbitration process, so the guy can't "just issue a chargeback" and be done with it. Also, credit cards are tied to identity, and anyone that issues fraudulent chargebacks may lose their credit card or have other penalties applied. Heck, if it's for a large enough value, maybe they'll get arrested for fraud!

Regarding bitcoin double-spending, FWIW, a few years ago when MyBitcoin.com shut down, they claimed it was due to a series of double-spend attacks that were successful because they were only using 1 confirmation: https://bitcointalk.org/index.php?topic=34770.0. More recently, GHash.IO successfully executed double-spend attacks against BetCoin Dice, although it looks like they may have been using 0 confirmations?

[cgjaro]

The risk for credit cards is there. And yes it really is as easy as issuing a chargeback and maybe claiming your card was stolen. The only reason it is not occuring more often is because most people are honest, that's all.

I demonstrated to you that accepting bitcoins is safer than accepting CCs in most scenarios like (1) when the merchant's half of the transaction is cancellable, or (2) when the merchant waits for enough confirmations. Now in the last scenario (3) where not only the merchant does not wait for confirmations but the transaction is non-cancellable (eg. guy walking away with laptop), nothing inherent to Bitcoin PREVENTS the merchant from taking all the same precautions he takes for credit cards: for example he could check your ID, check your credit score, verify your presence in his own database of high-risk customers, etc. Bottom line is neither in (1), nor in (2), nor in (3) is Bitcoin inferior/riskier than CCs. In fact it is clearly superior to CCs in 2 out of 3 scenarios. There was a great Mashable article recently explaining merchants love Bitcoin precisely for this reason: http://mashable.com/2014/08/06/bitcoin-retailers/

MyBitcoin claim they were using 0 confirmations, not 1. (But many in the community and myself included think their whole story was a lie and that instead MyBitcoin stole the bitcoins, but I digress...) BetCoin also was using 0 confirmations.

[eridius]

> The only reason it is not occuring more often is because most people are honest, that's all.

Well that, and the fact that it's fraud, which is a crime, and if you get caught then you will get in trouble.

> I demonstrated to you that accepting bitcoins is safer than accepting CCs in most scenarios [...] when the merchant waits for enough confirmations

Even waiting for 1 confirmation can still take 10 minutes, which is a long time to wait for a lot of transactions, especially in-person transactions. That alone makes it extremely difficult to use Bitcoin for "real-world" transactions as opposed to online transactions.

[cgjaro]

Now, eridius, you are starting to repeat a point you already made and that I already rebuked. This is a sign you have no way to "win" this argument and you are merely trying to have the last word :)

So I will repeat the rebuke I already told you, but I will repeat it only ONCE. After this, if you repeat yourself again, I am done here, since you are wasting our time. You are bringing up scenario (3) and my rebuke was "nothing inherent to Bitcoin PREVENTS the merchant from taking all the same precautions he takes for credit cards: for example he could check your ID (like some supermarkets do in the US), check your credit score, verify your presence in his own database of high-risk customers, etc" Therefore Bitcoin with 0 confirmations is no more risky than credit cards to accept in brick-and-mortar stores where the customer can run away after paying.