In this short communication, we discuss some key behavioral economic (BE) biases that likely minimize HIV prevention efforts, explore why certain key populations such as men who have sex with men or transgender women-may be more likely to succumb to these biases, and suggest how incentives informed by BE can support these populations in their effort to remain HIV-negative. Based on our formative work in an ongoing study, we discuss two important insights regarding the use of incentives to inform future HIV prevention efforts. First, participants often expressed more excitement for prizes that were viewed as fun (e.g., movie gift cards) or luxurious (e.g., cosmetics gift cards) rather than necessities (e.g., grocery store gift cards) of the same financial value and suggests that including an element of fun can be a powerful tool for incentivizing safe HIV-related behavior. Second, participants preferred not to be "paid" to display health behaviors, indicating the way incentives are given out (and perceived) is central to their success. Going forward, a BE perspective can help improve the impact of incentives - and increase their cost-effectiveness by carefully adapting them to the preferences of their recipients.