I have the following issues with the idea of BTC retail transactions:
1. Confirmation Time: It takes @ 10 minutes to get the first confirmation that a transaction has been processed. How does that compare to a credit card swipe? Win for the existing system.
That's really only an issue for point of sales. Anything that ships, there will be plenty of time for confirmation. Low value stuff like mp3 downloads, the amount of double spend fraud will be really low.
And there is a solution, green address -
https://en.bitcoin.it/wiki/Green_address2. Price Volatility: The volatility is enormous relative to day to day transaction costs -- how would you like your paycheck to vary by 10% from day to day. Win for the existing system.
True, but you can adjust prices of goods to the 7-day weighted average, there are free API's already for getting this info.
3. Wallet Security: Finding a secure wallet is not easy. Concepts such as hot and cold wallets don't inspire confidence. Why bother when I can just swipe or pay cash? Win for the existing system.
Actually wallet security I think is a strength for bitcoin, software wallets on a device. Web-wallets I don't have a lot of confidence in.
4. Regulatory Risk: Certainly an issue for fiat/crypto exchanges which may or may not apply to merchants in the long run.
This is the problem making it hard to obtain bitcoin in the United States and needs to be rectified.
5. Payment Risk: No recourse if you send payment to the wrong address
Sending to the wrong address is really difficult to do because of the checksum that is part of the address. It is highly unlikely that a typo in entering the address will result in a valid address.
The vendor simply provides a URI that can be clicked or QR-scanned and typo isn't even an issue.
6. Public Key Length: No one can deal with the length of those keys, it's either an alias or the QR code. QR codes aren't really familiar to most people. Establishing alias's takes time and a little bit of sophistication.
Vendors just need to provide a URI. The specification has existed for some time, and I believe virtually all wallets work with it.
It doesn't take more than one of these issues to turn 99% of people off. Until these basic problems are solved, I'm not surprised that the Bitcoin economy hasn't grown as rapidly as some would hope.
The main one is the regulatory issue making it difficult to obtain bitcoins. In my opinion.