We used some similar a few years back to mark sidewalks and they worked and held up well. I see they make 48" stakes now and probably going to order a 200 starter set with the tool this week. We still use the ol' 4ft wooden stakes and painted them with our company colors but that's getting to be a pain to do and probably 3 times the cost so if these are as nice as they look probably going to order 500 more.
I saw some somewhere that had little flags on them with your business name and # on them. Now I can't remember where. Ballard products has some that reflect light, they aren't solar. So when you drive in and your lights hit them they will shine. They are spendy, but you are supposed to spread them out with the cheaper ones