I was having one of those "over coffee" meetings yesterday in a small cafe. We'd never been there before but the decor was inviting. After the preliminaries of who was having what had all been taken care of, and I had indicated to the waitress behind the counter that I was paying, I stepped forward with credit card in hand. I vaguely recall hearing the cafe's landline phone ringing off to one side, but I didn't pay attention because, well, I was in the middle of paying for my group's tea, coffee, and snacks. The waitress serving me evidently did pay attention, because she picked up the phone and answered it. And started dealing with the caller. While I was standing there with a credit card in my hand.
I don't wish to sound like one of those customers, but my instant emotional reaction was to feel insulted. "Wow, am I that unimportant to you?" I was a real, tangible customer - one who had shown a general interest in products and services (by being in the cafe), shown my specific interest in products and services (by stepping forward and listing the things that my group wanted), and had shown a willingness and ability to pay (by holding out my credit card). And still the waitress thought that I was less important than an anonymous caller on the telephone. For all she knew the caller was a telemarketer offering great deals on a timeshare investment.
Whatever it was, the call retained the waitress's attention as I paid for our food and drink. Without hanging up or putting the call on hold, she took my credit card, processed the transaction, and allowed me to leave the counter without a word. I returned to the table. The experience must have shown on my face because one of my group asked what was up. I related this story, and was told "you know, that makes a great little case study".
And that's what this is.
Your current customers are more important to you than anyone else. Look after them. Don't let your desire for more customers negatively impact on the service you provide to customers you already have, because customers have choices and may choose to go elsewhere. A real customer standing there in front of you with her credit card in her hand right now is more important to you than the possibility of a hypothetical customer somewhere down the track if you just take that phone call.
As the saying goes, a bird in hand is worth two in the bush. We'll be having our over-coffee meeting somewhere else next time.