There's probably a great deal of merit in the analysis that you suggest, Philip, but, to be honest mate, my working day consists of:
Check emails
take & make phone calls
Buy cars
Expose cars to danger of sale (ie prep 'em & advertise 'em)
sell cars
go home
drink beer & watch football
rinse & repeat
I'm not sure there's enough hours in the day that can be spared for non-productive number crunching, however beneficial it may appear. I just get a feel for what works and what doesn't.
Not very scientific, but the bills get paid.