Hello,
this is usefull for all users not just cetrain web website.
A lot of users need a functionality to link to one or many external web sites.
Similar modul is
JumpMenu
It is a drop down menu and when you choose an option it is a link that takes you to another website or sub-domain on your website.
FC filter modul filters results on your website but does not have functionality that takes you to another web sites.
And this is very useful as some times you need to show information that is on another website.
Linking to another website is always useful.
Joomla core menu has a functionality you to create a menu that is a link to another web site.
The links does not take you to FC categor they just take you to another website ULR