First of all, what is RSS?
RSS stands for Really Simple Syndication and allows you to syndicate your site content. RSS is an automatically updated XML list or ‘feed’ of defined items on a site

Why Use RSS?
RSS was designed to show selected data. Without RSS, users will have to manually check your website for new updates. There is so much on the internet today for people to keep up on, so this is just too time-consuming for many users. With an RSS feed (RSS is often called a News Feed or RSS Feed) they can check your site faster using an RSS aggregator (a site or program that gathers and sorts out several RSS feeds) or a live bookmark.

Since RSS data is small and fast-loading, it can easily be used with services like cell phones or PDA’s. Web-rings with similar information can easily share data on their sites to make them better and more useful.

Should you use RSS?
Webmasters who seldom update their sites do not need RSS. Websites that archive or maintain old information do not need RSS.

RSS can be useful for Web sites that are updated frequently, like:
News sites - Lists news with title, date and descriptions
Site changes - Lists changed pages or new pages
Companies - Lists news and new products
Calendars - Lists upcoming events and important days
Posting - Lists latest posts from a blog or forum

The Future of RSS
RSS is going to be everywhere. Thousands of sites use RSS and more people understand its usefulness every day. By using RSS, information on the Web becomes easier to find and web developers can spread their information more easily to special interest groups. Hopefully, future RSS versions will include additional fields that will make it even easier to categorize and share.