Well, swallowing a premium (both by discounting yourself or adding a tip) definitely creates an incentive. It's a sacrifice that each of us must decide to take or not. The % itself is also a factor. I'm sure almost no bitcoiner would mind throwing in a 1% tip to an upcoming bitcoin-accepting business, but I would also assume most people wouldn't be willing to put a 300% one.

To be honest, I'm not that fond of it. I am of the thought that we need Bitcoiner businesses, not simply businesses accepting Bitcoin. The distinction is in the knowledge and conviction. A bitcoiner business to me is a business where the property has fallen through the rabbit hole to some degree and accepts the Bitcoin because of that. A business that simply accepts Bitcoin to me is one that doesn't care about Bitcoin or the ethos and just wants to get more customers through the door. No bad feelings, I'm just missing a distinction.

Okay, going back to your idea: Bitcoiner businesses don't really need an incentive, they are already onboard. Your idea might be interesting to bait new businesses to become Bitcoin-accepting businesses. But there is more effort required for that seed to grow and, without more effort, things probably won't follow through. If you put a hefty tip, you are at risk of attracting pure opportunists that won't be there the moment that bonus is gone. That's why I don't like it so much. It can lead to start-and-crash situations which are not truly good to promote sticky adoption.