Emergency callouts
Power off. Tripping circuit. Burning smell.
The caller is on their phone within minutes of the problem. They search 'emergency electrician [borough]' or 'electrician near me' and call whoever comes up first in the map pack. Top three GBP results take the call. If you're not there for your core boroughs, that work goes to someone else — often someone with a weaker record but a better-optimised profile.