The frequency of your charges depends on your billing threshold.
When you first start running ads on Quora, you will be charged when you hit your billing threshold, or on the first day of the following month. Whichever comes first.
The first threshold is $25 USD, and rises with each successful charge to $50, $250, $500 and $750. The same value thresholds apply in all currencies (converted to the local currency). We automatically charge you when your spend hits $25 or on the first day of the following month, whichever comes first.
If your account spends less than $25 before the end of the month, any costs incurred will be charged the first of the next month.
If your $25 charge is successful, then we won't charge you again until you spend an additional $50, or on the first day of the next month. Whichever comes first.
An account with a $25 threshold starts a campaign on January 1st.
If the campaign spends $25 on its first day, the account is automatically charged $25. This charge will appear as a "Threshold" payment on the Billing & Payments page. The account's billing threshold will also increase to $50.
If the campaign spent $20 between January 1st and January 31st, nothing is charged to the account in January. This is because $20 is below their billing threshold. To cover the unpaid balance from January, the account is charged $20 on February 1st. This will appear as a "Monthly" payment on their Billing & Payments page.