According to Jakob Nielsen, the usability guru, the RSS will never substitute the email marketing. Fistly because receiving a personalized newsletter seems warmer and more powerful medium to reach your audience. Secondly, it seems that only few people- mostly techies-  like to customize their information  through RSS feed.

Moreover, most of the people showed confussion regarding the term RSS. Few of them knew the meaning "Really Simple Syndication", so Nielsen suggests to call them "News feed" instead. This way it will be easier to guess what they actually are for.

While RSS feed are a fantastic tool to keep updated with the latest news of your interest, it can also be seen as other obligation for the Internet users who will need to check another space regularly.

If you like to read all this article, you will find it at http://www.useit.com/alertbox/newsletters.html.