What Dan said, and also, if you don't offer such a convenient feature and your competitors do, then you'll be bleeding users no end. Better to have users getting a feed from your site (leeching bandwidth and not contributing to the community or your revenue in general) than to have them go and get their RSS from a competitor (this would apply more to a Digg style site than a blog of course). You can always monetise the RSS feeds later (Tom's Hardware, I'm looking at you...)