You seem to grasp this already.

I usually write OO modules, and as far as I have understood, using Exporter on object-oriented modules isn't really necessary, as 'all' methods should be connected to an object.

Right.

... this module is procedural, and it uses Exporter to 'publish' its two methods into the namespace where it is used.

Right.

It is useful for making it easy for procedural modules to publish symbols into the namespace where they are used.

Also consider Exporter::Lite, Exporter::Simple and other Exporter::*.