in reply to Sending Data
This sets your form up for possible abuse. Say I didn't like my coworker and I filed out the form a bunch of times with his address and checked the box. Next thing he knows he is getting spammed from everywhere. You should make sure that you have a database to compare with so the user doesn't get submitted multiple times. Or better yet, send a comfirmation email to the email address submitted and have the owner of the email address just reply, if they truely want the promotional emails
Please remember that no one likes spam!