Keep this in mind, this can point a finger right at us one man band operations. Are we definitive in doing all we can to increase sales while inside the home? Are your techs doing all they can to increase sales?
Remember that there has to be a catch or financial reward most times for those who work for you to promote more sales at the home. And I'm not meaning anything by deception or overpricing, I mean by suggestive selling, explaining the entire job and the cause and how why and what needs to be done, the options along with opportunities when it arises.
When it comes to leaky faucets, I'll point to it but I will not say, "would you like us to fix that while we're here?"
My approach is,
"I just wanted to point out that I see this faucet leaking and this is a well known symptom of the system trying to relieve itself of the high pressure." Now, not every leak is gauged to high water pressure but if you've done your job as a plumber and was called out to touch anything water pressure related, you better know what pressure you're dealing with, always. No "guessing" by looking at water leaving a faucet, that's the homeowner's assumption, never yours if you got any scruples to your value as a plumber.
When you see an open floor drain with no cover on it, those cast iron ones, you could say, "Hey, you know what? We might have that size in stock on the truck" and if you have them, do your best to sell it. I saw a guy pay $56 dollars for a 10" cast iron drain cover!!! Talk about overpriced! He bought it at a plumbing supply house. No way that was that much on the true numbers.
If I had them on the truck, I'd go for $10-$20 markup and keep it at that.
Lint traps, $5 and you can buy them for less than $2.
Aerators are another item you can sell but always see how rotted the old one is coming out; you might enter the unknown if you try to take one out and it won't come out. Kinda like opening a can of worms so to speak.
But your workers can add a significant amount to the gross earnings every day if you make a point to sell something, anything to get more money in your pocket. Like those little plastic triangles made as water shields to keep the water in the tub. No more than $5 tops and you can get up to $10 depending on who you deal with.
It's all in the attitude, showing the objectives to people. So often in service, the service plumber knows apple for apple, take a bad one and put a new one in. But exploring the cause and what-ifs to a customer will sometimes become a very receptive conversation and you've completed your goal by saying, "Well let's just go ahead and get the whole thing done, get it right."
By far, your customer, your consumer will greatly appreciate this mentality than dealing with common recurrences just because they didn't spend the money when they should.
Giving them "hope" guidelines also makes a difference. I sometimes reference myself and say that I'd put it at a 7 on the level of seriousness in dealing with a problem or a range that is honest and suitable to how serious the plumbing problem really is.
You never know if the customer is going to use you once or 10 times. All I know is keep trucking along like it doesn't matter if it is a one time experience or not.
People like variety, I love variety. I don't get my hair cut at the same place every time...I just don't.
I in past never used the same tree trimmer, even though they've all done a decent job. It just all works that way and it's hard to explain why it happens, that's why I can't get too upset when I see it happen to me.
Freedom of choice is something we all agree on.