There is a "rule of seven" in marketing that says that consumers need to see a brand's "message" 7 times before they become familiar with it and feel comfortable enough to buy. Every touch point, including your link as an payment method alternate to PayPal, adds towards improving familiarity. Providing a discount is a nice incentive to drum up a little additional interest!
this is true, but having bitcoins flashing in your face 7 times in a 2 minute period EG at the product listing page, as a side advert, at the payment page. does not truely count towards the 7 times.
usually people psychologically log it 3 times.. still pay fiat. but a few days later they return and take more notice of it, and thats the more likely time they would convert. which is still faster then a returning customer making 6 transactions before converting.
so dont expect every customer to take on bitcoin first time. but returning customers will. dont expect a high conversion rate of first time customers. and never expect a 100% conversion no matter how much you plaster bitcoin logo's on your website.