You can hide Parallels promos only by editing the panel.ini configuration file.
To hide Parallels promos:
panel.ini from the following directory on the Panel-managed server:%plesk_dir%\admin\conf\
If the file does not exist, create it.
[promos]
<promo_id>.active=false
The <promo_id> may be one of the following:
You can hide your own promos in a similar way.