5. Subdomains or Sub-folders
Since search engines keep different metrics for domains than they do subdomains, it is recommended that webmasters place link-worthy content like blogs in subfolders rather than subdomains. (i.e. www.example.com/blog/ rather than blog.example.com) The notable exceptions to this are language-specific websites. (i.e., en.example.com for the English version of the website).
The Google approach is even; there is no difference between the two, however it is *recommended* to use a subfolder.