1. Go to "Tracking".
2. Scroll down the page to the section that says "Conversion Tracking Count".
3. Click on "Switch To One Conversion" to track each conversion by IP address only. If you are running a leads campaign, you would probably want to switch to track one conversion only so you are only tracking unique leads, even if the same person opt-ins multiple times.
To switch back to "Every Conversion", simply click on the "Switch to Every Conversion" button. You would probably want to track every conversion if you are running a sales campaign and you want to track every single sale that comes through.