Was just looking at my Google analytics stats for the last couple of years since I first set up analytics and I noticed something that could definitely be construed as proof that blogging benefits your website hits and general internet presence. See Below:!
If you notice the dates, theres a nice upward curve from about when I started blogging in earnest, you can have a look at my Archives Page to see the correlation between this graph and my first tentative blogging months!!
HERE is some more info on the SEO value of Blogging & WordPress in particular.