Basically, the higher your page rank is, the more the search engines will favor the text on your site when people search them for those words. (It's actually a lot more than just that but for the purposes of this example, it's close enough). Obviously, you should have as high a page rank on your site as possible with 10 being the highest you get. Generally, anything above a 3 or a 4 is considered good. A page rank above 6 is very good and 7 or 8 is exceptional.
It is important to understand that page rank is NOT linear but logarithmic. (Actually only Google knows the real formula as it is a closely guarded secret). It works something like this:
Page Rank Actual ranking
0
Unranked No one has ever heard of you.
All sites begin here
1 very low
2 very low
3 low in top 100,000,000
4 moderate in top 10,000,000
5 In the top 1,000,000
6 In the top 100,000
7 In the top 10,000
8 In the top 1,000
9 In the top 100
10 One of the top 10 sites period!
From the above, you can see that there is a vast difference between page rank 3 and 4 or between 4 and 5. As your site moves up in rank, so the competition becomes more fierce. For example, if you have a page rank of 6 you may be one of the top 100,000 sites. To get to a rank of 7, you need to be one of the top 10,000 sites. To have a page rank of 8 would mean you are one of the top 1,000 sites (in the whole world remember) - a huge difference.
