I've ordered shoes online several times, but I had a specific brand and model or style of crosstrainer that was consistent and well built that fit perfectly. I've worn out four pair.
Went to re-order and found out that particular item has been discontinued.
The good news is, I ordered the replacement model and they are perfect. I can only tell the differences because I have an older pair to compare.
I got really lucky!
I hate shoe shopping!!