Excellent Question!
My site started out at 18 and in 12 months I have increased it to 38 with the help of suggestions on this site. My goal is to hit 40 by the end of the year. I did this by
#1 Created 22 new root linking domains. (including a few paid from the list of suggested domains on SEOmoz.
#2 Changed my URL's to be more keyword rich
#3 Improved SEO on site with Optimization tools on SEOmoz
#4 Improved content
It has been fun and exciting. I know that if I improve on all the SEOmoz recommended metrics that it will help my search rankings and gradually help me against the competition.
New Things in process to get us to the 50 mark!
#1 Blog
#2 Better landing pages
#3 Web development
#4 More links to pages deeper in site
#5 Continued optimization of webpages on site. etc
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