While I admire the purpose of this service, I feel that it's of little use in actually reporting spam anymore since more and more of the reports I submit end up only being forwarded to 'devnull' addresses, meaning that they're only collected for statistical uses rather than being forwarded to the email service providers from which the spam messages originated.
If the primary purposes of submitting the reports is to have the service providers be made aware of the spam being generated, then this service is unlikely to be of any use/consequence.