Why didn't you mention the Lightning Network? It's fast and cheap, so it must be one of the reasons for Bitcoin owners to get encouraged to pay with Bitcoin. So, it must also be offered.
But it all boils down to what's in it for them if they opt to pay in Bitcoin. You have to take note that the most hassle-free form of payment is still cash. Cash is still the king. So, the only reason for them to be really encouraged to pay in Bitcoin is a discount, a cashback, a ticket or qualification for a raffle, a coupon for something else, or anything that they get out of paying in Bitcoin, a kind of reward for choosing a different payment, something they aren't used to.
Most people still confused about lightning network, so it's not a convenient way to encourage Bitcoin adoption. How can we expect people will pay through lightning network if they didn't even know what's the difference between non custodial wallet and centralized exchange lol, only knowledge users and experienced are know about lightning network.
You don't really have to understand the technicalities about Lightning Network. You just have to be aware that it is much faster and cheaper that way. That's enough for them to be encouraged, that is, if they're paying in Bitcoin, anyway. And you don't actually have to do much in order to use it. Your Bitcoin wallet like Blue wallet, for example, has it. All you have to do is create a Lightning wallet, put some Bitcoin in it, and that's it.
But my point is, if you're accepting Bitcoin payments, give your customers a cheaper and faster option. It's up to them which they prefer.
It's true discount and cashback would attract people to invest in Bitcoin, but honestly I don't know if these promotions are worth for stores' perspective because Bitcoin isn't a company where they will get more money after built a reputation (by giving free money at the beginning).
You know what, I agree. There's a little sense of altruism in here actually. If I only have business in my mind, I really don't have to accept Bitcoin payments, much less sacrifice a portion of my profit for it. There's not much I can earn from it, anyway. But we're Bitcoin supporters, so we contribute a little to its adoption.