What does "take too long" mean in this sentence?
I'm reading a selling book. but i find a confusing sentence:
"If you made a good approach, the customers will be glad you called her no matter when you call — unless you take too long"

Question

What does "take too long" mean in this sentence?
I'm reading a selling book. but i find a confusing sentence: 
"If you made a good approach, the customers will be glad you called her no matter when you call — unless you take too long"

Answer

"Take too long" means "take too much time." (In English, we often describe time as being "long" or "short".) So when the sentence says "unless you take too long," it means that if you spend more time talking than the customer wants you to, then the customer will NOT be glad you called.

Answer

This sentence is the same thing as 'if you wait too long to call'. The point is that the customer will be happy no matter what time you call, but you cannot wait too long to do it.