It is often small, inexperienced business people who go for this kind of thing, belieivng that some business is better than none. In reality you can only afford to do this type of work if you can assign a couple of days a week to it and take the losses, but be doing profitable jobs the rest of the time. 100 jobs is going to take a lot of time and apparently you don't get paid until you've completed them, so not only are you losing money on every job, you don't even get it in your hand till long after. Yes, you can upsell on some of them and recoup some of your losses, but the rest of the time you're dealing with people who only bought it because it was cheap. And, the other huge problem is the time it takes for a customer to need a re-clean, what's that, a year - two? So no repeats to earn from for a considerable time.
It will certainly be insteresting to see how Monty goes on with this, I wish him luck.
Simon