Among all the speculation and ancedotal evidence of people who think they have google “all figured out” on how to get the best ranking, finally there is a way to see the truth.
A german company called sistrix recently analyzed the top 100 Google SERP’s using 10,000 randomly generated keywords. As a result of that they were able to find some commonalities in the algorithm. This is a brand new study.
Keywords in the title tag
Targeted keywords in the body tag
Keywords in H2-H6 headline tags seem to have an influence on the rankings while keywords in H1 headline tags don’t seem to have an effect.
Using keywords in bold or strong tags - slight effect
Keywords in image file names
Keywords in image alt attributes
Keyword in the domain name - although, using domain names as link text may explain this
Web pages that use very few parameters in the URL (?id=123, etc.)
Inbound links - The top result on Google has usually about four times as many links as result number 11.
Keywords in the file name don’t seem to have a positive effect
The file size doesn’t seem to influence the ranking of a web page on Google although smaller sites tend to have slightly higher rankings.
The critics are criticizing this study because they haven’t seperated the variables independantly. In other words commonality doesn’t prove causation. For example, if everyone on a plane is found to be wealthier on average, that doesn’t mean that being rich causes you to be on a plane.
To me there seems to be a lot of factors that I know Google plays a significant importance on that they haven’t mentioned in this study. The only one that sticks out like a sore thumb from these findings is on the H1 tags. This is just a theory on my part, but it may be that websites who overly abuse the H1 tags, without using multiple deeper headline tags, are seen as less structured by google and less deserving of a higher rank.