There has been a movement to support "open data" that parallels efforts to make journal articles "open access".
Making your data publicly accessible is a service to other researchers. Doing so can help others replicate your results, or enhance your research impact, or give your research greater credibility.
You may want to mention relevant open data repositories if you are submitting a data management plan for a grant application. See the pages titled "Data Management Plans" and "Lehigh Preserve and Data Repositories" in this guide for more information.
For assistance with data sharing, contact the Research Data Management Team.