Profile Pictures, What are your Thougths?

As I am wading through these changes on Southern Somedays and it's associated pages (Twitter, Facebook,Pinterest, etc.) I have been wondering about Profile Pictures and how folks feel about them.  For a long while I have used my "M" initial as my profile across the board, but just recently put up my photo as a profile picture on my Twitter page.  So, my question is...do you like a photo profile picture on a blog and associated pages or do you care one way or another?  I have read all kinds of things about branding and social media so I am wondering if I should put up my photo or just stick with my "M"...thoughts???