Are parliamentary engagement initiatives effective? Do they add to the quality of democracy? And how can they reach a wider audience? These are key questions which, when answered, can improve a parliament's engagement strategy significantly. This article illustrates that the answers to these questions can be found by establishing a feedback loop, through which a parliament can not only improve the quality of engagement, but in doing so, boosts participation. It draws on the data derived from research conducted for the IPU Global Parliamentary Report (GPR). More precisely, this concerns a focus group, a parliaments survey, as well as a plethora of interviews which were conducted to get individual, accounts of engagement. The findings indicate that through careful evaluation, impact assessment, and transparent reporting of findings, parliaments can finetune engagement practices and generate incentives for engaging. Additionally, guidelines are presented on how best to establish a public engagement feedback loop.