Use this cronjob in combination with Advanced ratings mode.
Execute it like this:
cd /path-to-your-wp-installation/wp-content/plugins/amazon-simple-affiliate/scripts bash script.sh Asa2_Cron_Ratings
It is recommended to execute the ratings refresh cronjob every three minutes.
Replace [wp_path] with the local server path of your WordPress installation.
0/3 * * * * /[wp_path]/wp-content/plugins/amazon-simple-affiliate/scripts/script.sh Asa2_Cron_Ratings
To learn more about cronjobs, see Introduction.