The missing piece here is that 'empathizing with your customer' is an extremely different context than 'having empathy for others'. The former focuses on meeting your own needs through using 'the skill of empathy' to create a bond of kinship and be more likely to execute a sale. The latter focuses on understanding the needs of others, even if — especially if — doing so does not advance your own needs.

I am courteous to those around me on phone support calls and in businesses because I can understand — I can empathize — what they've been through with other people yelling at them, mistreating them, and gaslighting them. I may not be friendly, I may not be effusive, I may not be agreeable — I certainly am not known for being agreeable — but I will do my very best to keep it together, because I've been yelled at before, and I would consider that a grievous harm committed upon another.

I think one time I was grinding my teeth I was so angry that they could hear it on the phone, and my voice was flat, tense, and cold to the bone, and I made specifically sure — even amidst my rage at the harm committed by their employer — to thank them and say goodbye politely. It wasn't a warm goodbye, but it was definitely courtesy, and I don't think they expected it.

The comments up and down this post fail to distinguish these two definitions. In both cases, you're "understanding how the other person feels" — literally, empathizing — but it's how you use that information, and to whose benefit your use serves, that is causing such confusion in the replies.

If someone walks into your store purposefully and doesn't want to make eye contact, empathy suggests that you should let them be and keep an eye on them. This is a great example because they clearly don't want to be hassled by you, and you clearly shouldn't allow yourself to be shoplifted from.

If you use empathy to persuade people to buy things that they'll regret buying once they've left your store, that's generally considered a variation of 'evil' and is the subject of fables and fiction, not the least of which being an absolutely terrifying rated-R book called 'Needful Things' by Stephen King. People will leave some of the angriest Yelp reviews you've ever seen for a business that uses this tactic, not just because they feel taken advantage of themselves, but specifically to protect others from feeling that way. They literally empathize with your future customers and will do their best to warn them away.

So, when someone says "show a little empathy", they're telling you that you've prioritized your needs higher than those they think you're disregarding as irrelevant. They may or may not be right, but that's a very common context for negative comments about your skills at empathy.

It's also common for kindly people to have absolutely no clue what's going on in other people's minds. You'll see them hold the door for someone who's about to drop three bags of groceries — missing the forest for the trees, so to speak, but still genuinely making an effort to care at no benefit to themselves. They'll be confused and sad when you drop your groceries, because they would have helped if they'd realized.

To restate this all in dry terms for nerds like me — The default context for "show more empathy" is a request that you increase the priority of donating your energy and time to social support of others without expectation of reward to yourself. In specific contexts like Sales and Marketing, it means not only "listen more closely to the customer's needs" but also "understand that sometimes the customer's needs may prevent the sale". And you can flip this around, too — if someone says "you have to put up some shields", they're usually telling you that you're going too far with your concern for social support of others, and need to back it down a notch and worry a bit less and take care of your own self.

I hope this will help you and others align your definition and uses and contexts of the word "empathy" more closely with the world's.