Credits are Roolz currency. It is necessary for those who work on the private exchange. Now you can buy additional private offers placement with credits, i.e. above your plan limit.
To buy credits:
Log in to your profile at roolz.net and then to the space of the company you are working on behalf of.
Click on the "Settings" button located in the upper right corner.
Select "Plan and billing" tab on the left.
Find "Credits balance" and click "Top up credits".
Enter the number of credits you would like to purchase and click the button "Top up credits".
Enter your card details and click "Pay".
Purchased credits will immediately appear on the "Credits balance".