One thing is for sure: 
 I'm going to get the sequel ASAP and finish this trilogy. 
 I had a reading slump at first, but I tried to pick this up again and I am impressed on how its story goes, quite cliche but still an enjoyable read. It was an easy read and indeed fast paced. I absolutely love it! 
 Karma is a bitch. 
 This book is all about friendship and revenge. Three girls with different pasts & personalities bonded to plot their own revenge to those people who hurt their feelings. It seems a bit childish but I did enjoyed their pranks. Good girls gone bad (except for Kat, because she's already a kick-ass one). Out of the three, I think Mary stood out the most. Her story was a huge impact and quite sad that you just want to hug her for real. 
 I'm also a fan of Kat, whom I considered the strongest and the bitchiest. Her personality is really striking and she is the motivator in the group. I loved her for that. I love Lillia, for being a protective sister and being the smartest but she needs to be more confident about herself that she isn't afraid to face her fears. 
 What a good start. I can't wait to see more. :)