Free, is the most expensive

I will repair the computer, basically a small computer problems, I can repair, was in sunshine, home repair computer is charging very high, so high level to know more, I decided to play ad: Students start internships Free home repair computers.
Is really free, but certainly higher than the fee income is even higher, because most computer problems are related with the anti-virus software, I would recommend RISING Antivirus to them, 180 per set, they generally will give me money, I to buy the equipment on behalf of, and generally I bought a set, you can use to 10 users, while I am a free call service, so normally they would drive me to school, or asked me to dinner, will take something gave me.

So then, as Ma said, "Free is the most expensive", that is very reasonable, they can spend 20 yuan to find personal site service, and looked me free, not just to ask me to dinner, but also Rising to buy my anti-virus, but also help me to introduce business, introduce your friends to know.