Note that all this is supposed to change with Evolution. The plan for Evolution is currently to target merchants to pay the fees. So a regular user who uses Dash under X times per month, will not have to pay any fees. But after X transactions, it's assumed they're using Dash as a business, and fees start being charged. How exactly this will work, I don't know. I don't remember seeing any actual plan, but they want to make Dash like any other payment industry and put the burden on the merchant, not the customer.
I believe they want to keep the fees at or below 1%, which is much higher than what it costs to send coins today, however it's also much lower than any current industry standard. If it works, this could make mining profitable forever. A lot of people wonder how miners will collect enough fees to make it worth while to continue to mine when the rewards virtually disappear? Especially if there is no room in the block (or no pressure for room in the block, as it is in Dash, to drive the fees up)? So either everyone will have to pay high fees in coins like Bitcoin, or miners will stop mining due to fees being too low as in Dash (and remember, we need that "pressure" of mining competition to keep the blockchain secure!)
So once again, Dash might have the best solution. We shall see if it can be implemented
I see many difficulties in enforcing this, so???