Newb question: RSS FEED benefits

Hello,

im not entirely new to BH but I still have not found a good explanation why RSS feeds are so good? I have read that many use them, but i havent understood the benefits of it?

Is it something like this that You great a blog or etc and send out your feed to attract more customers. Do you get backlinks of your feeds or smth?

Or are you just scraping feeds to your site so You could get fresh content on Your page so its frequently updated? Wont non unique news harm Your ranking?

Sorry for such dumb questions - perhaps i havent found a right thread that explains it

Thanks

search engines or blog always look for new content and they look in rss
just a little secret if you want to update a blog do it every 30 minuts for infos
-http://feedity.com/plans.aspx

good luck