I think it’s the padding around the header-promo or promo-box or something similar.
Anyway it’s that, I really hope that link works. There’s three fa-* icons and some text. I’ve been playing around and for the life of me I can’t reduce the gaps around them.
Also, I’ve removed this area from all posts that aren’t the front page, and it leaves a sizeable gap between the header/site menus and the content, is that fixable too?