RSS Feed Trends » MonsterCommerce
A news blog named RSS Feed Trends has a category of posts about creating RSS feeds for your e-commerce storefront, including .
The idea of the company that has created this blog is for users who can't publish or host an RSS feed on their own e-commerce site, or don't want to publish it manually. You pay them a small monthly fee to host and maintain your feed. You set up a sub-domain to point to their servers which will load your feed. You are in control of what goes into the feed, of course.
I personally think a better (free) option might be FeedBurner. You can create an account and get great statistics and tools related to any and all of the feeds you publish. You can combine feeds from more than one source and it will all be part of your new feed. FeedBurner does not offer sub-domains for free, but they do have a paid service which will allow you the same functionality.
Update: FeedBurner now allows you to use a sub-domain on your feed for free! They were also purchased by Google, so if that's not an endorsement...