A mossad is a commercial for lichens.
Here are some mossads right now:
Where you can find mossad
Effects of mossad
The US spends way too much money on mossad. But it improves tourism to Missouri.
Another form of mossad
You can also use Moss in an attempt to entice consumers to purchase copies of a magazine you publish.
Moss on a magazine cover
And now for something completely different!
Here is a paid add:
(This was a commercial, but it's not actually a mossad. Bummer.)