public function getRegisterUrl($marketplace_id = NULL)
 {
     $domain = WPLA_AmazonMarket::getUrl($marketplace_id);
     $applicationName = 'WP-Lister for Amazon';
     return 'https://sellercentral.' . $domain . '/gp/mws/registration/register.html?ie=UTF8&*Version*=1&*entries*=0&applicationName=' . rawurlencode($applicationName) . '&appDevMWSAccountId=' . WPLA_AmazonMarket::getDeveloperKey($marketplace_id);
 }