I saw that merchants can keep whatever percentage they want in Bitcoin. 

> Merchants need fiat to pay their bills, so they cannot afford to convert 100%, but depending on their cash flow and appetite

Not if they can pay their bills in bitcoin.

I hope there are some options to do a mixture as well. Merchants need fiat to pay their bills, so they cannot afford to convert 100%, but depending on their cash flow and appetite, if they keep a few percent of their revenue in BTC that will signal a massive adoption too.

bitcoin

Square terminals to allow pay in $, receive in btc tomorrow

Scoresby

Or the other way round.  

I hope there are some options to do a mixture as well. Merchants need fiat to pay their bills, so they cannot afford to convert 100%, but depending on their cash flow and appetite, if they keep a few percent of their revenue in BTC that will signal a massive adoption too. 