(...) people are motivated by several factors when presented with a PWYW opportunity; the most basic of which, is the desire to uphold their opinion of themselves. Giving more than is necessary in an anonymous way causes people to feel good about themselves. On the other hand, the offer is less appealing when being asked to pay in view of others, such as fellow patrons or the owner of a restaurant. In such a scenario, people feel forced into paying a certain price. They also shy away from opportunities when they feel pressured to buy at a price that is too high, hence those that choose to not buy at all, even when allowed to pay whatever they wanted. (...)