This topic has been discussed frequently and the range of opinions on the wisdom of trying to build a business from this type of work is wide and has also been thoroughly discussed.
A couple major challenges to consider are the terms of payment, insurance requirements, etc. and how hard it is to collect from an out of state entity. These companies are notorious for slow payment unless you are the only option in an area.
Then there is the assumption of liability for another company's work from permitting through bond issues, accidents, miscommunications, vendor imposed deadlines, etc. You and your staff become the face of that company while on their jobs. You also will need to have enough secure storage to hold sign components and assume financial responsibility for them until they are installed. They also plan the timelines on projects around THEY and THEIR client's schedule not yours.
Most of the project documentation requirements are stiff and include online time management where your crew has to "clock in and out" through a project management portal, take voluminous numbers of photos to document the work. We've been forced to sign agreements about job site behavior, attire and personal hygiene requirements as well as having to arrange EVERYTHING with the store manager including documenting your time of arrival and departure. So you get to the work site and it could take an extra 15 minutes to find the manager, tear them away from what they are doing, then repeat when finished. I've been challenged a few times to lower my original quote because it took less "documented" time than the quoted amount.
It seems like unless you are in an area with a lot of malls filled with national chain retailers the amount of work probably isn't enough to build a successful business off of on its own.
Can it augment your own clientele and help fill in some empty space in your calendar, sure but not necessarily at YOUR convenience.
