again: many methods of SEM. Search engine optimization method is just one of the many methods of SEM, there are many SEM methods, pay for free can achieve the purpose of marketing. Pay method of bidding promotion promotion, advertising alliance; free methods of email marketing, social media integrated marketing, blog marketing forum, free resources cooperation marketing. These methods are in the website construction to achieve the SEM method, each method has its advantages, but also have some disadvantages, so for the construction site, want to have the effect of network marketing success, Shanghai dragon and these paid free promotion requires a combination of complementary approach to construction. This website, the effect will be brought to the site more ideal.