Wildlife sightings are not always guaranteed. To address this risk, tour operators often offer a money-back guarantee as a refund mechanism; however, studies have overlooked the influences of such refund mechanism on tourists’ tour participation decisions and tourism revenue. We conducted choice experiments to examine the impact of such mechanism using a case of Amami rabbit tourism, Japan. We found that the guarantee influences significantly both the decision-making of tourists and tour revenue. In particular, we found that the expected tourist participation rate and tour guide revenue vary drastically depending on the probability of the rabbit encounter; the maximum expected revenue from the tour with a 90% chance was about 20 times larger than that with a 10% chance. Sharing the findings that conserving rabbits to maintain the sighting probability raise tour benefits would lead to the win-win situations to balance conservation with tourism developments.