It can be difficult to find a normal width in relative low cost shoes like these.  Most stores only carry the wide width and soon, you foot is sliding side to side in the shoe or all the way to the toes.  This width allows for better support and keeps what arch support there is in the right place in your foot.  I have purchased this same shoe in the wide width and I really like the way they are made and the way they look.  Comfy enough for casual and even with a pair of khaki trousers--almost dressy.
I would have reservations about buying shoes without being able to try them on.  However, AVIA seems to build their products on a stable last--that is, the sizes are constant from one lot to another.