The point is a lot say schools-commercial are the be all and end all of WCleaning,the fact is they are if it’s priced correctly and you will keep them as long as you’d like to continue to clean them. The fact is this kind of work is done these days for a fraction of the price it once was due to multi nationals and larger firms cleaning them for no more than a daily rate,I know people used to clean large showrooms and supermarkets and earn 2-3 days money starting at 4am and finishing at around 10-11,not anymore those days are behind us.
i don't think any cleaning is the be all end all, schools are not regular enough to be that. however they are a nice addition, again a lot depends on the company, if your only making a standard day rate and pushing work back then its not worth doing - why jeopardise and delay your regular work ( altho many do this anyway ) but if there is a premium on it and you can adjust staff to fit it in then yes they are good, the same applies for any of our 1 off works, pressure washing, roof cleaning, graffiti removal etc..
also by having a school on the books you are more likely to get more - we clean an 'academy' school who have now taken over several others in the area and we are their first port of call for cleaning - not just windows but gutters as well
Darran