I keep seeing adds for bed runners are it looks like 2/4 wuilt with out batting

The ones I have seen have batting and are quilted.

if i made a bed runner, i'd put batting in it. without it, the quilting done doesn't show up well at all.
there are pillow toppers too, that fit over the pillows and are as wide or wider than the bed.

OK new and maybe a little goofy here but...what is a bed runner??

It's on the order of a table runner, but used on a bed in place of a full size quilt. Warmth for the feet or decoration.

Here is an example: http://www.quiltingboard.com/t-74445-1.htm