Rented a 10x20 online and got the discount... I'm military, so called the owner a few days early to see if I could get my code in advance, since I wouldn't be able to arrive during business hours because I was driving from a long way away; he was more than accommodating, and allowed me to pay over the phone and get my code when needed.
It turned out I was able to get there during business hours, which kind of through him off a little, as there was an insulation panel missing from the ceiling of our unit when I first showed up. He rushed and got it installed in about 15 minutes though, cleaned it all up, and had it ready to go by the time I started unloading... He even chatted with us for awhile and grabbed us some cold beverages. All-in-all, good experience, and good ownership. Would recommend to anyone.