I haven't seen many sign spinners around here in a few years. They were sort of a fad for a while there. I actually look negatively on the tax preparers that have the people dressed as uncle sam or the statue of liberty out on the street corner. I was somebody a bit more professional doing my taxes.
Where this does seem to work is in this one area where there are a lot of warehouses and strip malls. The warehouses that sell furniture and such direct to the public have sign spinners to tell drivers that they're tucked back there. It works for me.