As a freelance writer, I have to work with SEO on regular bases so I know what it is and use it often. Yet I never used it in my own sites until recently when I thought I would see what the hype is all about anyways? So I started using it a few post back and since then my analytics and blog visitors have at least doubled. You can see a real screenshot from my Google analytics account and see how my most recent post(which is where I used SEO) has affected my blog. You may have to click on the actual photo first though, to get a closer look at it.
Granted, with my posting more often likely helped some of that as well. But this post here is to give all of us bloggers hope that with a little hard work and some good SEO skills, you can also slowly get more visitors as well.