Just by simply telling them that they can have good profit on it will be an effective thing. It's like an additional payment method to their whole business, they won't sacrifice the cash method or fiat system for it. Because bitcoin will be added as an option to their service which will good for other customers that are into bitcoin.
Yeah paying with fiat and credit/debit card will always be there as majority of users will prefer to use the same method and the fact is they may not be aware about bitcoins but if merchants starts accepting bitcoins as a mode of payment then it will really help people who are using bitcoins.
Exactly that is what I'm pointing out, because the awareness about bitcoin is spreading that is why we only need to give them clear details on what is bitcoin and almost everything we know. Let's disclose too some of the problems about bitcoin but I guess it will not be a big problem.