Name on blog sign up

Hello,

We are running a pro sites blog and it is running great. The issue is sometimes people either don't complete the sign up process or they may sign up and not finish their website.

I am trying to add a "Name" or "First and Last Name" field to the sign up process and their profile so that we can contact them on Facebook. (Most of them are in our niche group).

I tried this article, but it did not work - http://wpadminuicustomize.com/blog/how-to-customize-for-register-form-for-multisite/. I am hoping that you are able to help me find a solution because I have lost a few customers since I can't find them (even via email).

Thanks!