>>5888185 (OP)It's literally not possible. Geosync orbit is 22,500 miles away and that sign would have to be 5,000 miles wide to be seen. It probably wouldn't need lightbulbs at that point because they could design it to reflect the sun in all directions in front of it. But, still. No.
They could do a low orbit like the ISS but then it would still have to be like 10 miles wide to be readable, and it would only be seen by each location on earth a few times a day and only at night, and only if people are looking up, and only for about 5 minutes.