Using free content to drive more valuable offers and paid services.
This infographic is bang on. Blogging accounts for a huge portion of our website visitors each week.
One of our articles by Mark Lynch, "3 Habits of Highly Effective Inbound Marketing" has (so far) been shared/viewed by over 750 visitors.
The general consensus is to publish at least one article per week to stay fresh in search. We agree with that, but add that when we've published a second blog in one week, the result is always increased site visits.