I am working on an existing CMS. We were thinking if it would be usefull to work with a cronjob. When thinking on this, we could only think on updating the search index for the cronjob, so we have no idea if we should add the cronjob to our CMS or not …
What do you think?
Are you asking whether or not it would be useful, I think that it absolutely can be for certain tasks.
Having done some Drupal development, I know that it tends to use cronjobs for aggregating feeds, caching pages, creating logs and a whole host of other things.
see http://drupal.org/cron for a more in-depth example/explanation.