The emergence of knock-off phones can be attributed to several causes. The most important one is that the elimination of technical barriers in the mobile phone field has opened the door for large-scale production of knock-off phones. Capital from all sides has flooded into this market, ranging from handicraft workshops to enterprises that can compete with some domestic brands. There are countless manufacturers of knock-off phones, and they are mixed in quality. Especially in October 2007, the cancellation of the "mobile phone license" system implemented for a long time (9 years) has made some knock-off phone companies emerge from the underground and become legitimate players. A detailed分工 knock-off phone industry chain is gradually taking shape. This is also the beginning of the formal entry of knock-off phones into the mainstream market.