I am not in the business of SEO, but a lot of my business comes from the Internet so I feel it is good to know SEO. 

When I first started learning SEO, I would compare mostly page rank and some traffic rankings along with the on-page optimization.  Nine times out of ten I could not figure out how Google came up with their ranking for a particular keyword.  I spent hours trying to figure out what the main difference was.  I then came across WebCEO, which was a great tool.  It compared on-page factors along with off-page factors.  It would show all the links Google may be counting along with all the links Yahoo! may be counting.  I figured this was the best tool I had ever seen.  So I ran some comparison reports on certain websites and...... it still did not match up to what Google was showing on its rankings for certain keywords. 

Then I cam across SEOmoz.  I actually was at first interested in it just to read the Q & A's, which by the way are very helpful.  Then I started to try out the tools.  When I ran comparisons on certain sites, I realized that SEOmoz pretty much matched up to what Google was showing......Hallelujah....the answers to my prayers!

If you are just reading through things like I was a few months ago, hopefully I am saving you time by telling you go ahead and get your Pro Membership now. IIf you are a Pro Member, hopefully you agree with me. If you are SEOmoz, I want a cookie for each person that signs up after reading this post.