In residential service the average invoice may be as low as $500 with a net profit below 10%. Even if you raise the average invoice and net profit, what is 90 minutes of your time and truck worth? Free estimates can have a major effect on the bottom line.
Large projects, net profits over 25% and commercial maintenance are another story.
Yes free estimates on residential can have a major effect on the bottom line, 90 minutes of overhead and operating expenses, can cost plus or minus $ 180. Throw that much on the street a few times a week, and you may reach the bottom in no time at all.