When I first started this site, it was "APLAWRENCE.COM". That's the name of my company, it's not overly long or hard to spell, so it seemed to be a good choice. However, later on I registered "PCUNIX.COM" thinking that that name is more related to what I do, is shorter and easier to type, and perhaps is more memorable.
Both domains point to the exact same content. The Apache configuration file at my web server just treated them both as virtual domains having the same filesystem location. There was no difference: no matter what domain name you used, you'd get the same pages. These are just duplicate domains.
For several years I flopped around, using the names inconsistently. When I'd refer people to my site, sometimes I'd send them to pcunix.com and sometimes to aplawrence.com, depending on my mood. Of course other sites that made link references to pages on my site were just as inconsistent: some of them point to pcunix.com, some to aplawrence.com, depending upon their whim or how they happened to find me.
Google Page Rank
It turns out that was a bad mistake. Google (and other search engines) don't really know that these are actually the same site, so they index the sites independently. That causes problems for ranking.
Google uses a lot of undisclosed criteria to determine how "important" they think a page is. One is incoming links: other sites that reference your site. In Google parlance, that's a "vote": a site is voting for your site's page rank by referencing it in a link. With two apparently separate sites as I had, that caused a dilution of votes: some sites link to pcunix.com, some to aplawrence.com, and therefore neither really gets the votes they really have.
Worse, Google apparently will penalize sites it thinks are too similar to other sites. As these sites are really identical, that could cause Google to downrate one even more than it might otherwise. I've seen people complain that one of their duplicate domains actually went to a Page Rank of 0.
So having duplicate domains isn't a good strategy for web site popularity. As that popularity drives business to me and increases my advertising revenue, it's very important to me that I get the best ranking I can in search engines, and especially in Google.
In June 2003, that's where I was. Something had to be done.
What is my Page Rank?
Ah, that's a good question, and it turns out not to have an easy answer. If you want a heavy on the math but still interesting dissection of this subject, see http://www.iprcom.com/papers/pagerank/.Otherwise, for a sometimes inaccurate look at Google Page Rank, download the Google Tool Bar for Internet Explorer (unfortunately Google doesn't provide this for any other browsers). It will show a gray/green bar for any page you visit. The more green, the higher the Page Rank. If you hover your cursor over the bar, you'll see a numeric score, expressed as X/10. This is apparently a logarithmic scale, so a rank of 2 is much more important than 1, etc. The problem with this is that there are reports and indications that it is not always accurate, but as it's all we have to go by, we can probably trust it to the extent that a page rank of "2" is definitely much less popular than a rank of "4".
Ah, that's a good question, and it turns out not to have an easy answer. If you want a heavy on the math but still interesting dissection of this subject, see http://www.iprcom.com/papers/pagerank/.Otherwise, for a sometimes inaccurate look at Google Page Rank, download the Google Tool Bar for Internet Explorer (unfortunately Google doesn't provide this for any other browsers). It will show a gray/green bar for any page you visit. The more green, the higher the Page Rank. If you hover your cursor over the bar, you'll see a numeric score, expressed as X/10. This is apparently a logarithmic scale, so a rank of 2 is much more important than 1, etc. The problem with this is that there are reports and indications that it is not always accurate, but as it's all we have to go by, we can probably trust it to the extent that a page rank of "2" is definitely much less popular than a rank of "4".
By the way, I've found Google's tool bar to be strange in other ways. For example, if I just call up "aplawrence.com", I get a Page Rank of 0, while "aplawrence.com/index.html" gets 6, as does "www.aplawrence.com" and "www.aplawrence.com/index.html". They are all, of course, the same page.
So, back to my problem. The pcunix.com site main page had a Google page rank of 4, while aplawrence.com had 6. So, if I could merge them together, I'd get 10, right? No, because it's logarithmic. I *might* push it to 7 if my present 6 was close, but there's no way for me to tell that ahead of time. No matter what, getting the two to be one has to help. So which one should be the "real" site. Well, no matter what attachment I might have to "pcunix.com", the "6" page rank says that's the one to concentrate on. So I needed to get "pcunix.com" to become "aplawrence.com".
301 RedirectWell, there are a couple of ways I could approach that. I could just kill off pcunix.com and hope that the sites that link to it will eventually find aplawrence.com and change their links. That sounds like a dumb idea.
I could move pcunix.com to its own content and put up big banners asking people to change their links. That doesn't sound much better.
Finally, I could use a "301" redirect, which is what I did. The first thing needed was to set aside some space for pcunix.com separate from aplawrence.com. In the htdocs (the html root) directory, I put one file named .htaccess which contains this:
redirect 301 / http://aplawrence.com/
I then changed the Apache configuration to point pcunix.com to this area, restarted Apache, and I was done. It's that simple: any request for any page at pcunix.com is redirected to the same page at aplawrence.com.
Time will tell how this will affect me. I'll check back here in a few months and update this page with what I have learned.
Some good places to discuss this sort of thing are http://www.ihelpyouservices.com/forums/ and http://www.jimworld.com/.