I have done loads of transactions and all my unconfirmed transactions have been confirmed and bitcoin credited
Some merchants will ask customers to wait for the confirmations but what is the actual risk? and what could happen other than the transaction being confimed?
I made one without fees that did not get confirmed for ~8 days IIRC. I had to double spend it, which is what merchants are afraid of. After enough time has passed most (if not all) nodes will forget about the transaction and its unlikely that it gets confirmed. I could create another transaction that spends the same inputs, but instead of paying the merchant I pay someone else. Should my new transaction be confirmed the old transaction becomes invalid and can never be confirmed.
Which payment processor did that merchant use for your order?
I did not order anything, I made a TX to myself in order to fuse 4 small inputs into a bigger one without paying a fee. It failed, I paid a fee. It could have been a payment to a company though.
Aren't they are able to seperate transactions with and without any fees?
Sure, a merchant can also rebroadcast my transaction without fee which would make it very difficult to double spend it. There are several counter measures to double spends. E.g. a company could contact a miner directly and to get such a transaction confirmed with priority even though it has no fee.
That's quite an important feature, especially for the protection of merchants.
I have yet to see a service that refuses payment if the transaction has no fee. A high priority TX without fee will confirm fast anyway, its not like the fee is the only indicator.
I had one without fee and it took almost 10 days to get first confirmation,if your transaction is legll, then it will eventually get confirmed.
While thats not wrong eventually might be a very long time. I still have an input for 1 satoshi. I would have to wait ~10 million days for it to have a high enough priority to get confirmed without fee.
