Why does gladwell use the word “bargain” instead of “agreement” or “deal”?

Gladwell uses the word "bargain" to set the tone of the essay.

Explanation: While "bargain" and "agreement" have the same meaning, they are used in different scenarios. Both words mean an exchange between two parties, but bargain means something was traded for less. The word "agreement" or "deal" suggests a more positive tone, where both parties were able to exchange with equal value.  

in my opinion, anyone should be allowed to marry as long as it's not going against any laws. though i kind of contradict myself because i know that in some states and countries, gay marriage isn't legal yet- hopefully you get my point.

why did you delete the answer?