I started in on roofs last year using New Again. It works well. Have only done walkable pitch roofs so far but looking to get into steep roofs (=high dollar houses=more money) too. Problems I am facing are safe access and minding OSHA regulations. While I don't have OSHA looking over my shoulder, I have employees covered by Workers Comp. If they get hurt (especially bad) OSHA could start snooping around and I better have my ducks in a row. If you have ever read the CFR on Fall Protection for roof work...well you best think about it before you put a man up there. Also, my level of Workers Comp insurance really isn't at the roofers level so I want to avoid having any kind of mishap. Currently, my employee would be covered in case he got hurt from a roof job but then my %rate would soon increase to the roofer level. Obviously keeping the rate LOW is best.
Another OPTIONAL SERVICE that I am planning for this season is the installation of sacrifical zinc strips to prevent the roof stains once the roof is cleaned. There is a compnay that makes the strips and if you buty in quantity, they are pretty cheap. If you are on the roof anyhow to clean it, putting the strips on is just cash in the pocket. Then you'll be the guy that solves the problem not just another roof cleaner.