Since the affiliate reports are daily reports, you do not have to run the reports more than once a day.

Manually Generating Reports

By clicking on the "Run Report" link, you can generate the daily affiliate reports between the last day on the reports to yesterday. You are supposed to run the reports daily, although you may do that once every few days.

Automatically Generating Reports

Using cron job to automatically generate affiliate reports daily is the better way to go, if your server supports cron job. You need to setup a cron job to run the script ‘run_report.php’ in the plug-in folder. You may either run the script as a shell script from command line, or use wget command to run it on the web.

The cron job should be run only once a day. It is recommended to run it when the site has less traffic, for example 1:00AM. For more details about how to setup a cron job on your site, please see the help documents of your web hosting service or contact them for help.