Here’s a simple means to increase the number of subscribers to your blog: promote your RSS feed. When you comment on another blog, instead of leaving just your blog address, leave the address to your feed. This highlights your blog as well as suggests that your blog is fantastic and worth subscribing to via RSS.
Why would you wish to increase the number of subscribers? Theoretically, more RSS feed subscribers leads to a wider audience of readers. And more readers inclined to read/skim each post. Which leads to greater exposure for your blog. Which is a good thing.
(Found some time ago via doshdosh)