I bought the ManhattanGMAT SC book from Chapters.com (Canadian bookstore). I'm currently going through the book and last night I decided to register online for free practice tests. But when I entered the serial code that came with the book, the site didn't accept it saying an invalid serial number. I tried several times but it didn't work.
I took the chance and emailed ManhattanGMAT and complained to them about the problem. Today I received their reply and now I have my free CATS along with the question bank.
There response really made me happy. Although the book itself is worth buying, but their customer service won my praises too.
I hope I can utilize these resources and score a 700+ (or how about a 750+

)