Getting her e-mail or her phone number?

Letsbond answers:

There are many reasons why a man should ask for a woman’s e-mail rather than her phone number.

First of all, she will be more reluctant to give her number to a stranger and even if she does, she might not answer if you call her because she does not trust you. However, if you get her e-mail address you can write her something and she is more likely to respond because she has time and she can see from your e-mail what you want.

Second of all, it is easier for both of you. When you are going out and spend too much time talking just to a girl, there is the possibility you will never date and you would have wasted the whole night for nothing. Instead, you can briefly talk with one girl, get her e-mail and then repeat this a few times with other girls. Then, you can decide who you liked most or go out with all of them, get to know them better and figure out who would you like to spend your time with the most.

E-mails are more efficient and women feel less pressured when a man asks for their e-mail address. Moreover, if you send her an e-mail you give her time to respond when she is comfortable and this is something women appreciate.