You get a title on chess.com if you have a chess title in real life. You first have to earn a FIDE title and then I guess you should submit proof to the staff here.
How to become an NM, GM or FM on chess.com

Lol,you have got it all wrong!Dan Heisman is a National Master,A title which you get by getting a rating of over 2300 USCF if im not mistaken,He hasnt achieved the title because of chess mentor,he has achieved it by earning a 2300 rating in USCF Over the board tournaments.There is no other way of earning a title other than doing well in tournaments,you cant earn a title by having Chess Mentor ratings or such.
How to become an NM, GM, IM or FM on chess.com? I've seen people with 2000+ not having a single title, and others around 1900 having a title, for example look
http://www.chess.com/members/view/danheisman
this guy is unrated, but he has a title since he is good in chess mentor, there's no chess mentor in real life, therefore he shouldn't earn anything, chess.com invented chess mentor and chess tactics...
Anyway, how do you earn a title on chess.com? What should be your rating? And do you have to participate in tournaments if you want to earn it? Or you can earn it just by winning any games?