^This. As I understand it, serifs form a horizontal channel that guide the reader through long passages of text (ie. in books, blog posts). For long lists print

^This. As I understand it, serifs form a horizontal channel that guide the reader through long passages of text (ie. in books, blog posts). For long lists printed vertically, sans works better because there are no serifs to interrupt the eye path. This is why bullets work well - they guide the eye vertically down the page.