I agree its important to get out to the customer as quickly as possible to give your quote, getting there first before some silver tongued natural salesman does mean the difference between getting the job or not, of course you need a confident well rehearsed pitch especially if your not a natural salesman, as I am not.
I would say don't be affraid of asking if you can pop over in the early evening if your booked with work the day of the call and so your not sounding like a desperado I just them 'As I'll be passing by your area after finishing the last job today' that way your reducing the chances of the customer calling on more cleaners for quotes, which if your telling them you can come to quote in a couple of days time I guarantee will happen, over a year I'm sure your conversion rates would increase - Don't delay!!
I gave a quote yesterday morning, the guy seemed very pleased but told me he had several other companies coming to quote later in the day -

So he was either a price shopper or I had failed to sell. Turned out a bit of both, I'm pretty sure I know who else quoted as he told me where he had seen me advertised - He rang back this morning asked if I could come down £25 !!! No, I don't compete on price -

I compete on quality of service

- Ok, can I have it done anyway. Jobs a good un.
Paul Kinder Clean