The neon signs covering every inch of Stem City are an important part of its business and culture. If a business doesn't have a sign or a broken sign, it is normal to assume the building is desolate and that it is okay to bunker down inside.
The neon signs themselves are easy to configure and decorate, requiring a cheap tool brought into the Nexus in bulk. They require very little power and only have one power cable. Small businesses exist around the southern sector to set up these signs for the locals.
Large businesses exist in the northern sector that allow companies to bid for space and time on massive neon signs decorating the city's busiest intersections. These specialized signs are hooked up to a small network that goes through the STEMNET.