看到几个英文帖子都是关于链接文字的，总结一下：
1，链接文字的重要性：
1) Anchor text is extremely important to rankings, especially in Google. Ive seen some evidence in Yahoo, but not to the extent that Google rankings can be influenced.
2) By identifying your pages through relevant keyword links you are "telling" the search engine which keywords the linked pages represent. The rule applies for both internal and external anchor text."
2，怎样写链接文字
1) Make it easily understood by the user. Be honest about the anchor text. What it says is what you should get.
2) Important link positioning top left to bottom right. (throwing tons of links at bottom helps little).
3) Exact anchors that best support the content on the link to page. Its great to use tons of links where the anchor text suggest importance to "web design" however if the page is specific to "web development" then the use of "web design" link anchors will be less effective.
4) The use of "broad" has the benefit of aiding "broadly" e.g. using links to a website about "college degrees" where the link indicates "degrees" has the benefit of gaining associate degrees, bachelor degrees, masters degrees, as well as the specific subject matter for the degree itself link computer science degrees.
A link anchor however about "masters degrees" dilutes the value to other degrees e.g. bachelor degrees - so it is a game of tradeoffs.
5) If attempting to do item #4 for "web" to capture "web design", "website design", "web development", "website development", a text link anchor looks quite inappropriate. Thus the value of image links e.g.
Code:
<a title="web" href=""><img alt="Web" src="web.gif"></a>
where the broad term is less apparent and the image actually reads "web design".
3, 争取外部链接时，反向链接文字用相同的还是不同的？
-问题： I have been reading conflicting advice regarding link building. Some sources claim that you have to use the same anchor text all the time, while others claim that G may penalize you for doing so. Can anyone comment on this?
-回答：
1) It is a good practice to actively change your anchor text and in fact, you should, to point it towards all different pages of your site, instead of just linking to your homepage. By doing this, you strengthen your site within the rankings for all your pages and relevant terms. Yes, this does take time, however; it is the most beneficial way in which to completely stabilize your site within the SERPs.
2) From what I have gleaned you should definitely change your anchor text but it should all point toward a theme.
3) The engines, especailly Google, are looking for "real" links, not contrived links. The biggest red flag of contrived links is if they all read the same. The best way to be real is to mix it up a bit.
4) 针对"The biggest red flag of contrived links is if they all read the same. The best way to be real is to mix it up a bit. " - I agree, but I dont think google is really going to care until they start seeing a lot, like thousands of links coming into the sight. Until then its just not enough to be considered that it is not just a coincidence.
4，关于title和alt标签
1) A senior Google engineer told me the other day that placing title tags inside the href tag will improve optimization. I am slowly integrating and it is helping a little with terms that were floating on second pages moving them up slightly.
2) The alt tag is useful only with graphics. You cannot use the alt ATTRIBUTE (not tag) inside the href tag.
3) Alt tag is for an image, title tag is for a link... so in some cases there could be both as in: <a href="domain" title="great cheese"><img src="cheese.pic alt="great cheese" title="great cheese"></a>
4) I have noticed that Google does view titles in links and if all the links on your page have the same title text, it will view it as spam. It also does not like special characters in title text. Just my own observations.
