RSS stands for ‘Really Simple Syndication’. In simple words it can be explained as - "If you have a blog with RSS, a reader can subscribe to the RSS feed and receive updates from your blog. So if you publish a new article, the user will be notified. This makes it so that readers don't have to check your blog every day looking for new content."
RSS is a very good way to keep your visitors informed about any updates you have made or any new Topic you have  posted. So the readers who are interested in the same topic that you are blogging about they will keep on coming back if you have some good content to write about.
So giving an option to Subscribe to your RSS feeds make it easy for the people to come back and stay updated instead of they typing your complete website's address or every now and then keep checking your website if they have bookmarked you.
So this means that it makes it much easier and convenient for the people to stay updated.
Giving an option to subscribe to your RSS feeds also gives your visitors an option to, not to come at your website or blog but directly read it from feed readers. So what will you do now, if people don't come at your website or blog  then how will you earn online? or how will you earn from your blog or website?
Thats when you place ads in your feeds, which i will continue in the next chapter, about "Making Money from RSS by placing your advertizers ads in the RSS."