It's for verification purposes. When you sign up for the free trial Videostripe may charge and refund one or more variable amounts to your account up to $2 in order verify the card is valid, and that you are the authorised and legitimate cardholder. These amounts will appear on your card statement along with the corresponding refund.
If you cancel your account within the free trial period (7 days), you will only see the verification charges and it’s corresponding refunds in your statement. If you do not cancel your account within one week your account will be automatically extended to a premium account at the cost of $49.99 per month.