How do add-ons work?

The Pro plan by default supports 10-minute tests, and this can be extended up to 1 hour with add-ons. Add-ons are $25 for each additional 10 minutes, so to add 50 minutes it would be $25 * 5 = $125. Just like the Pro plan, the monthly cost is pro-rated, you have access to the features added by add-ons for the rest of the month, and your subscription renews automatically at the beginning of the next month. 

If you have a need to test longer than 1 hour, we do support this. A support representative will need to configure your account to allow you to purchase more duration add-ons. If you'd like to do this, email and we can do this before you purchase an add-on.