One of the aspects that attracted me to bitcoin was the fact that there are almost no fees.
But I was just looking at Blocktrail's optimal fee calculation and they say that you need around 26 US cents (0.00057565 BTC) to have a 75 percent chance of getting in the first block. For a low priority transaction 14 US cents (0.00029540 BTC) is needed.
These numbers seem a bit high. I've had no problem getting confirmed quickly with 0.0001 BTC transaction fee and recently I have had loads of transactions confirmed with no fees, so it is still possible. However even a fee of 0.0001 BTC (at 4 cents) will be 8 cents when the price of bitcoin doubles. Then will the optimal feel be 50 cents?
A lot of other ways of moving money around (Venmo, Wepay, Apple Pay, etc) are not half as powerful as bitcoin, but they are cheaper. None of the systems mentioned involve any fee for the user.
Now I use purse.io and fold app to get discounts. I use bitcoin for international remittance because it is cheaper than the alternatives. Even though I love bitcoin, if each transaction will cost 50 cents I will want to use Venmo or Wepay instead.
Andreas Antonopoulos mentions often how bitcoin will help the unbanked and the poor in third world countries in Asia, Africa and Latin America. But in a lot of the places I've lived, 10-50 cents can buy one a meal. Will people living in those kind of situations really want to fork out 50 cents just to get the transaction confirmed in a timely manner?