Secrets of RSS

Another thing to consider when you start a new RSS feed is the number of possible readers. Having thousands of people checking your Web site hourly for updates could be a problem if your Web server limits your bandwidth or, worse, charges you for bandwidth over a certain amount per day. You might end up with substantial costs, or some readers might not be able to get your feed.

On the other hand, RSS is XML, which means it's text. That's good because text is relatively small, so it won't take too much bandwidth to send. Still, there are a number of things you can do to avoid taking too much bandwidth to support your feed:

• Don't put an item's entire text into your feed if you have pages and pages of text for an item. Just put the first few paragraphs into the RSS item and add a link to the full story on your Web site.

• Don't include images in your items. You can add HTML to your RSS items to download images.

• Check out a caching service like www.rsscache.com. Caching can help you reduce your bandwidth needs. A caching service stores your feed, and you get a URL to use for your feed. Your readers use that URL to check if there's anything new, and the caching service sends out items only if there's something new to send.

If you're working with readers you know, you can ask them to change the frequency with which their RSS reader programs check for updates. For example, SharpReader lets you set the time between updates in the Options dialog (Figure 10.3).