RSS feeds is one of the most effective ways to spread the content of your site[s] on the internet. Basically, RSS feed submissions involve the bookmarking (submission) of the RSS feed link of your site[s] on different site[s] on the internet (Where the feature of RSS feed link submission is available ;)).
Once you submit your RSS feed link on the site[s], you do not have to submit the links of the updated content of your site[s] as it is automatically posted there
Hope this information is useful...