The concept of QBLChinese
 
A combination of
teaching conducted by
a computer teacher
and training given by
a human teacher
is the easiest, fastest and cheapest
way to learn Chinese (Mandarin)
 
Computer Teaching VS Human Teaching
Advantages
Cheap - Once you buy a computer teacher at a low price, you don't have to pay more money.   Interactive - a human teacher can talk to you and can answer your questions. Being with a human teacher, you would never be bored.
Powerful - a computer teacher usually contain all kind of study materials and study tools. Therefore, a computer teacher can do many things that a human teacher can do.   Being able to supervise you - a human teacher can supervise your study, telling what you should do and what you should not do. He/She can correct your wrong way of learning Chinese
Efficient - a computer teacher can read aloud a word or a sentence again and again for you, leaving a deep impression in your brain. And you need not to spend time on reviewing what you have learned.   Make friends - You and your teacher might become friends, after he/she give lessons to you for a period of time.
Never be tired - a computer teacher would never be tired. He can teach you something once and once again till you master it.  
Convenient - as the computer teacher belongs to you, you can ask him to teach you Chinese at any time. If he refuse to do that, just restart him. Computer teachers are especially suitable for those who have a busy schedule.  
Disadvantages
Unable to Talk - computer teachers' AI are usually very low, therefore they are not good at teaching you speak Chinese. And they are unable to answer your questions.   Expensive - if you hire a human teacher, you have to pay him/her at least $ 10 an hour. And you still have to spend time on reviewing what you have learned from him/her.
A little bit boring - as computer teachers can only do what is already programmed, you might feel boring after watching his the same reactiions day after day.   Would be tired - a human teacher can't read aloud something repeatedly for you, for he/she would be tired.
Unable to supervise you - if you are a lazy learner and don't study hard, a computer teacher is not able to supervise you. And he is not able to correct your wrong method of learning Chinese.