not for everything
any gutter cleaning ive done, (which is quite alot) i reckon a very small percentage would suit a gutter vac, no way you could clean out the stuff ive cleared, tiles, etc and very heavy clumps etc
besides by the time you have surveyed it my ladders are on roof of car and im finished
also what about downpipes, you still need to get the ladders off
if its a huge commercial gutter then fair enough but domestic is ladders, or if too high scaffold tower or small mewp i reckon, i honestly dont see point in gutter vacs i would love to see the same house done and timed with ladders vs gutter vac and see the difference in the clean too
but going back to original post , i reckon gutter cleaning is an extremely viable and profitable full time business model , especially if run with other services as the prices are great , only downside is drumming up enough work to keep it regular , which is where window cleaning wins
also marketing costs for keeping enough work have to be considered, at least windows, you keep your work for a long time
guttering seems quite seasonal too on the whole although saying that i picked two up this week but the rain has been heavy at times so people have obviously noticed it..
i reckon keeping a day or two a week free for guttering and having a window round would work pretty well