If you let other departments treat your community like a noticeboard, don’t be surprised when members ignore your community like a noticeboard.
A single job advert alone won’t do too much harm.
But it’s rarely just a single job advert. Soon it’s a single job advert and a product announcement, corporate video, news about the new CEO, press release, and new year’s greeting etc..
The same thing that makes the community seem attractive to other departments (more attention) is the same thing that the community will lose by posting these announcements there.
A better approach is to set standards and adapt each approach for the community.
Instead of a job advert, offer community members $500 if they refer someone you eventually hire. Let them headhunt for you.
Instead of posting a corporate video, host a competition and invite members to create, edit, or critically evaluate your own videos.
Instead of posting news about the new CEO, host a live AMA with the new CEO exclusively for the community.
Instead of a press release, ask members for their opinions on the issues and let them chat with your experts.
Instead of a new year’s greetings, let members come up and share their priorities for the new year.
Whatever you do, don’t let the community become a dumping ground for everyone else’s content.