Have a cleaning company here. This year my business made $400k. My main clients are property management companies and I mostly schedule move in/out cleans, office and apartment amenities and I have a few commercial spaces like small offices. Property managers and especially maintenance staff all talk to each other in their perspective areas so word to mouth is huge in this business and if you are consistent and readily available at a calls notice you will continue to grow. Now what everyone else is saying about standing out and being different is also correct for example my company stands out because we include baseboards and appliances in our base cleans and they aren’t extra charges which vendors really appreciate. Little difference like that can really make you stand out. I don’t advertise at all online almost all my business is word to mouth but what I have done in the past to generate commercial income was get the emails of construction companies and email new client offers and service lists and I usually get hits to submit bids. Construction companies are definitely a way into the commercial game. Hope this helps a little