I knew a guy who worked for a Wheelie Bin Cleaning company that was ran by one of my ex customers (I dropped him because he gave me a 'not this month, mate').
Anyway, the problems he told me was collecting the small sums of money invovled, and the administration of whose paid what; some who've paid in advance and who wants their bin cleaned when?
Coupled to the fact that this sort of industry never attracts the highest calibre of employees; I think the business failed because of the low-quality staff, poor management, and lack of proper administration.
I also know most of the guys were ripping off their boss; who they all hated.