How does Prerender bill?
Prerender operates a retroactive billing cycle. This means that we charge for 30 days prior to the invoice date. You don't pay for the amount of requests but you pay for the _recaching_ of your pages.
So if you for example have 20k cached pages with 7 day cache freshness, we will recache those 20k pages every 7 days for a month (that means that you have recached 80k by the end of the month and you get charged for those).
The pricing increases when you upgrade to a higher plan (which happens automatically). You get upgraded to a higher plan depending on the number of cached pages that you have. Keep in mind that the pricing also changes depending on the cache freshness, you can always check the units used in the invoices through the dashboard.
We always send an email to the email for the account when you reach 75% of your plan and when you're upgraded at 100% of your plan. You find more information in our Terms of Service.