There is no easy way for someone (who doesn't use RSS reader) to follow your blog without going through a few steps to get themselves "subscribed" to your blog. Take a look at the "Subscribe Email Updates" button on http://shimworld.wordpress.com/ and you'll see the Feedburner page it brings you to.
I currently have 100 email subscribers and 132 "followers" by RSS readers (also a Feedburner service—see bottom of sidebar). The Email subscription service works very well except there is one very annoying thing about Feedburner ... it sends a confirmation email link to the subscriber which needs to be clicked before the service is activate. What I've found is that many a time, that email gets filtered as spam and I'm left with many "unverified" subscriber which I would ended up deleting.
Too bad WP.com does not provide a more user-friendly straight forward to subscribers to enter their email address directly on the widget and be done in one go.