While Daniel is correct that open source projects require upkeep and typically require a community of users and developers giving back to the project in order to succeed or at least continue, I think this could be misused as a reason to back those that erroneously conclude that closed source software that is backed by paid work on software is the best method, and this in my many years of experience is incorrect.

Another correction is that "open source" does not mean free as in beer. Source can be open and not free. To ensure that you are using or offering source with a free license, please read: https://www.gnu.org/licenses/license-list.en.html