A big priority this year has been to simplify and empower admin's abilities to put content in various locations, such as sidebar, feed, etc. to have control over community design and messaging.
As part of this we honed in on the "Display Ad" component to build it out rather than build out a whole new thing.
Part of that is renaming this component to "billboard". You can still use it as an ad if you want, but in general this is the flexible optimizable box for lots of customization needs.
Heads up: We will be removing some functionality in place of doing more with billboards.
We will have a more official deprecation notice later, but billboards will ultimately replace "broadcasts" — and we will be deprecating "listings" as well.