Sometimes, it’s little things that trip up a business. Small business owners aren’t aware of seemingly inconsequential defects that affect a customer’s satisfaction and subsequent resistance to buy more, or even return.

For example, as a diehard tea drinker, I often find myself on the sipping fringes. This is a nation of coffee drinkers, and when I’m at hotels and coffee shops, I frequently find a hidden message: leave your tea-loving habit at home.

These places provide a good selection of teas — no issue with that. The problem is with the water. Too frequently it smells and tastes of coffee. Tea bags — especially herbal — are humble affairs, and I’ve not found one strong enough to overpower coffee-tainted water.

I’m guessing that the water gets run through the same system that filters coffee, and you end up with coffee-smelling tea water. I’ve asked for “clean” hot water directly from the stove, but the kitchen is rarely set up to provide it.

The problem is so common that I bring a thermos filled with my favorite tea to meetings. But while that lets me enjoy my tea, it doesn’t fix the underlying problem: the hotel or restaurant is selling a defective service.

Think about the services your customers buy. When was the last time you did a quality check? Are you continuing to deliver on the promise, or has a problem or two crept in? How do you know if quality has inched down? If customers don’t give you unsolicited feedback, I suggest that now and then you ask them how you’re doing. They’ll let you know if you’re lagging.

The best way to get honest feedback is to hire a professional to do your survey. Once you’ve settled on your researcher, let your customers know that you want to ask them a few questions about your services and the value they’re getting. Tell them that they can be completely honest, even anonymous, and that they should expect a call from your interviewer.

When you get the results, look for patterns in the responses. Obvious as this may seem, the response that repeats could be tripping up your business; it could be causing your customers to leave or to buy less from you.

In one customer survey I provided for a client the refrain was: doesn’t communicate well; hard to reach. After getting over the shock that something was seriously wrong, my client quickly set about repairing the two broken issues.

So don’t assume that if you don’t hear about a problem with your services that a problem doesn’t exist. Do the sniff test: if it doesn’t smell right, get out and fix it.