Well according to survey conducted by HubSpot the more frequently you post to your blog the more leads you generate. The study shows that Customer Acquisition through Blogs is Directly Related to Frequency of Posts If your blog is underutilized, you are leaving customers on the table. The 2011 survey shows a direct correlation between blog post frequency and new customers acquired.
You can get a copy of the complete report at-  http://www.hubspot.com/state-of-inbound-marketing/