I definitely have the cash flow problem. Which equates to not marketing enough. I've taken care of the rest though. Working on database customer list stuff.
Not buying the right equipment from the start, usually buying too small a unit, then needing to upgrade within a year. I'm not saying a V is for every business type, but I see many complaining that if they had known better they would have bought bigger from the beginning ( and bigger usually means #4 blower at least and for many a #5).
A V is definitely not for everyone, but it can fit your business model very well...and from experience I can tell you a V or AT will get a lot more walk ups than a 175 rpm scrubber!
Partnerships also seem to be a big problem with new business start ups.