Symbolic awards - i.e. any awards, like a badge, that are not monetary or of tradeable value - that are publicly given to newcomers to reward them for their contributions

Symbolic awards can increase newcomer retention and keep people engaged in a community by signaling that their contributions are valued and by using reputational incentives. This is particularly relevant for platforms that rely on voluntary contributors.

Gallus (2017) conducted a field experiment on Wikipedia and found strong evidence that symbolic awards can increase contributor retention. 

In the study, a number of newcomers to German-language Wikipedia who were deemed to have merited an award were randomly assigned either receive a symbolic award ("treatment") or receive no award ("control"). This award was publicly announced on the award's Wikipedia page and displayed on the contributor's personal page.

Contributors that received a symbolic award were more likely to remain active as a contributor and editor to Wikipedia after one month, compared to contributors in the control, with a 20% increase in retention. This effect persisted after two months (Note: All effects we include are statistically significant, unless otherwise stated.). 

In sum, contributors who received a symbolic award in recognition of their initial contribution were more likely to remain active on the platform for the next two months.

Community-driven platforms such as Wikipedia rely on volunteers as open-source platforms with a societal benefit. As such, volunteer retention is a crucial aspect for the platform to thrive.