Google的Matt Cutts确认Google五月份改变了网站/关键词排名的策略。 内页的权重不如以前好，如果你内页的外链很少的话。这种情况影响网站的长尾关键词的排名和流量，即使你是大型网站也不能避免。
I asked Google for more specifics and they told me that it was a rankings change, not a crawling or indexing change, which seems to imply that sites getting less traffic still have their pages indexed, but some of those pages are no longer ranking as highly as before. Based on Matt’s comment, this change impacts “long tail” traffic, which generally is from longer queries that few people search for individually, but in aggregate can provide a large percentage of traffic
This change seems to have primarily impacted very large sites with “item” pages that don’t have many individual links into them, might be several clicks from the home page, and may not have substantial unique and value-added content on them. For instance, ecommerce sites often have this structure. The individual product pages are unlikely to attract external links and the majority of the content may be imported from a manufacturer database. Of course, as with any change that results in a traffic hit for some sites, other sites experience the opposite. Based on Matt’s comment at Google I/O, the pages that are now ranking well for these long tail queries are from “higher quality” sites (or perhaps are “higher quality” pages).