Of course, nobody will know that your module exists until they notice it. Your module gets noticed automatically in many places, such as:
The "Recent modules" page of http://search.cpan.org
The "new modules" section of http://use.perl.org
A daily announcement in the "perl news" mailing list
An IRC 'bot on a few of the Perl-related IRC channels announces uploads as soon as they become available
An update or an uninstalled module in the CPAN shell, CPAN.pm
For greater visibility, you can also prepare a short notice to be posted to the Usenet comp.lang.perl.announce newsgroup. Just post the notice, and within a day or two, your news posting will be whisking around to news servers all over the globe.