Instead of buying traffic for specific profiles, you have the option to select "All Profiles" when creating an order. By checking this option, traffic will be sent to any profile in your account that is online. The order will update periodically to include all online profiles and exclude all offline profiles. This can be especially useful for users with a lot of profiles in their account.
Once you have checked this checkbox, you don't need to select any profiles. Just specify which traffic package and the system will take care of the rest.