I think shipping is very fast and a little fee is the best reason for consumers, in addition to making bitcoin wallet is not as complicated as paypal. and that is much better, there is no limitation in sending bitcoin
Bitcoin to bitcoin transaction is really comfortable.
But people are using their respective local exchange to convert their bitcoin into cash so still some of the details may still need for clients protection like Paypal is doing. Also fees applied depends on what type of cashout method they preferred.
I think it's because they are still not familiarized how safe bitcoin would be. It is a way protected exchange of money and things and for sure once they would get to know and see how safe it would be, then for sure they would really turn in to it. It is for us to introduce it to them that's all that we need to do.