gistfile1.php

<?php
class Demac_Casl_Model_Observer
{
    public function addCaslDataToSubscriber($observer)
    {
        $event = $observer->getEvent();
        $subscriber = $event->getSubscriber();
        $subscriberId = $subscriber->getId();
        if ($subscriber && $subscriberId) {
            $model = Mage::getModel('demac_casl/subscriber');
            $existingCheck = $model->getResource()->loadBySubscriberId($subscriberId);
            if (!$existingCheck->getId()){
                $model->addCaslData();
                $model->setSubscriberId($subscriber->getId());
                $model->save();
            }
        }
    }
}