"Talk to your customers" has multiple levels of meaning. Lets first deal with this advice literally... Do you speak to your customers, do you engage them, or do you just take orders, try to look busy, observe but not interact? Do you wait for your clients to call instead of reaching out and checking in on them? This advice applies whether you run a candy shop, an financial services agency, or a thousand-person virtual and bricks-and-mortar operation.
Don't react to your customers, reach out to them. Don't start the interaction by waiting to give an answer, ask you customers questions. Engage your customers proactively and drive the dialogue. If you wait for your customers to reach out to you, well they probably won't, and it's your business that's at stake (or if they do the chances are higher that you'll be in a defensive or reactive mode, rather than leading the conversation).
Next, and just as importantly, it's about how you are interacting with your customers. Are you engaging them on terms they can understand, on ground that they're familiar with? Are you accommodating them, or are you expecting them to get through your maze to tell you what they want? We've all been subject to telephone IVR systems that we know are designed to keep us from talking to a live person. This is a sin committed in more, and sometimes less obvious ways than a cumbersome phone system. When you undertake every task in your business do this one thing and it will help give you a better perspective.
Stop what you are doing, and try to experience it from the perspective of:
1. A new prospective customer, who doesn't know your business, but is currently considering doing business with you.
2. A current customer who has purchased from you before, and is at a critical juncture in terms of their level of affinity.
Reach out to these people, let them know that their opinions matter, better yet, provide a good old-fashioned Norman Rockwell-esque great experience, and you've just sewn the seeds of success through driving positive engagement.
One last point on this topic; when you create marketing materials, when you write scripts, when you select copy or imagery, and before you take a stand on social media or elsewhere... Remember who your audience is, who your customer is, whose purchases keep your home warm through the winter. Speak to these people, engage them, respect them, and don't operate your business from atop an ivory tower.