What is one reason you might want to use the Span Columns feature?
You have a bullet list of six items that you want to split into two columns in the middle of a text frame.
You are changing the number of columns on a page and want to ensure the text flows properly.
You want a line or top shaded borded to span across the top of a multicolumn frame.
You have a heading that you want to span across two threaded text frames