On the record, I can say that we absolutely can not prove that at this point. Off the record, there are many things that a blog does to speak directly to improving search engine organic placement, but we have no statistical proof that blogging improves your organic search engine placement.
This is what we do know about blogging and have been able to back up with statistical proof:
- Blogging increases site traffic between 25 to 35% over the same exact website that does not blog. (We found this out from a case study on three identical websites.)
- Blogging increases website stickiness
- Search engines spider and index your blog posts as unique web pages
- Custom FTP blog set up will allow blog pages returned on search queries to be shown with your website links in the organic search results. Versus posts for BlogSpot will not show affiliated with your domain in the search results even if you are using a custom domain BlogSpot setting.
- Typically posts done on BlogSpot even using custom domains will show at a lower PageRank level than if you had posted the same information with a custom FTP blog publishing setting. This is in part due to the fact that a blog set up with custom FTP will be able to piggyback on your domains popularity versus a BlogSpot blog having to stand alone.
- Sites that blog have more frequent search engine spider traffic.
- Even after a blog is abandoned website visitors will still read the posts
- Blog posts are read from between 20 to 45% of website visitors
I am working on a detailed new case study on blogging and will have some very interesting additional findings ready for posting on the Web in September.