Google has filed a patent application for ranking blogs using measures of quality, and Bill Slawski at SEO by the Sea has an excellent summary of the key factors. The quality factors fall into both positive and negative categories:
- Popularity of the blog
- Implied popularity of the blog
- Inclusion of the blog in blogrolls
- Existence of the blog in high quality blogrolls
- tagging of the blog
- References to the blog by other sources
- A pagerank of the blog
- Other indicators could also be used
Most of these seem like variations on Google’s typical use of “third party votes” to help rank websites. Bill has some good discussion of the individual points. The factors that could be negative indicators according to the patent are a bit more interesting and less intuitive:
- Frequency of new posts
- Content of the posts
- Size of the posts
- Link distribution of the blog
- The presence of ads in the blog
- Other indicators may also be used
Size of posts is a potential negative indicator because automated posting systems often create posts of identical or similar sizes. It seems like this could be an indicator for cheesy outsourced posts, too. I assume we can expect automated posting systems to start including more randomization factors now that this signature has been outed.
Traditionally, frequent posting has been considered a good way to do well in Google Blog Search. The patent app indicates that posting patterns may indicate spam, however, notably bursts of posts all at once or posting at extremely precise intervals. (More randomization on the way, no doubt.)
Unusual ad placement may be a hallmark of spammy blogs, too, e.g., inserting ads in the middle of posts. Kudos to Bill for summarizing this interesting document!
