This research idea explores the role of eustress as a mediator between technological uncertainty and user innovation. Based on theories of uncertainty reduction, it develops a competitive mediation model hypothesizing that the relationship between technological uncertainty and user innovation that is generally negative becomes positive when eustress is considered as a mediator. It also indicates that the attention performance of users moderates the positive indirect effect of technological uncertainty through eustress on user innovation such that this indirect effect is greater for higher levels of attention performance. A method for testing the model is suggested, and potential contributions are discussed.