If you're trying to let people know about new products that are for sale on your website, an RSS feed can be very effective. An RSS feed can be equally effective for short news blurbs or blog-style entries. The key criterion for an RSS feed to be effective is the frequency of updates. If you have information that needs to be delivered to your community on a daily basis, an RSS feed can be very effective. But if updates are only once a week or sparser than that, the fee feed will appear stale and will not be as effective.
For updates that are too few and far between for an RSS feed, dedicating a web page on your website for updates would be appropriate. A web page is also a better alternative to an RSS feed if you need or want to provide detailed information. Dedicating a section of your website to keeping you audience informed will provide you with the greatest flexibility but it is a fairly passive technique. Only the visitors who choose to visit that section regularly will see new notices.