[Plugin: Delete Duplicate Posts] CRON

Just installed on my site http://freeonlinecaradvice.com and have a question:

When I enable the CRON function, how offen will it run? (cannot an details in reference to this).

It would be great to see the ability to trigger via a web cron url!

Thank you,
WCC

http://wordpress.org/extend/plugins/delete-duplicate-posts/