• What is the value of SEO?

To understand what SEO really means, let’s break that sentence down and look at the parts:
Quality of traffic. You can attract all the visitors in the world, but if they’re coming to your site because Google tells them you’re a resource for Apple computers when really you’re a farmer selling apples, that is not quality traffic. Instead you want to attract visitors who are genuinely interested in products that you offer.
Quantity of traffic. Once you have the right people clicking through from those search engine results pages (SERPs), more traffic is better.
Organic results. Ads make up a significant portion of many SERPs. Organic traffic is any traffic that you don’t have to pay for.

• How does SEO work?

Baidu (or any search engine you’re using) has a crawler that goes out and gathers information about all the content they can find on the Internet. The crawlers bring all those 1s and 0s back to the search engine to build an index. That index is then fed through an algorithm that tries to match all that data with your query.

• What is Mobile Optimization?

Every year people spend more and more time on their mobile devices and tablets, but many websites still aren’t designed to account for different screen sizes and load times. Mobile optimization takes a look at site design, site structure, page speed, and more to make sure you’re not inadvertently turning mobile visitors away.

• How to improve my site quickly?

About content index:
o Good content supplies a demand
o Good content is linkable
o No duplicate for inside and outside
About content value:
o The trustworthiness of the linking domain.
o The popularity of the linking page.
o The relevancy of the content between the source page and the target page.
o The anchor text used in the link.If many links point to a page with the right keywords in their anchor text, that page has a very good chance of ranking well.

• How to evaluate the effect of the implementation of SEO
China SEO evaluation