Domain Parking Technical Details

Domain Parking is a term used to describe for temporarily placing a record in a nameserver (DNS) for later use. This is normally done ...

Domain Parking is a term used to describe for temporarily placing a record in a nameserver (DNS) for later use. This is normally done because you usually can't register a domain unless you provide a nameserver address, but many people buy domains before there is a website ready. Usually the domain is pointed at a temporary web page until the "real" site is ready.

The act of parking is physically the same as assigning a domain name to an IP address. Technically, you simply add an "A Record" to a DNS server and point it somewhere. Physically, it's exactly the same coding as a normal domain - what makes it a "park" is the contents of the destination - which is not a separate and unique site intended for the domain, but either a temporary holding page, an unconfigured server, or some other website altogether.

It will often look something like this:

www.mcanerin.com. IN A 192.168.5.100

The "www.mcanerin.com" is the domain name.
The "IN" is the Address Class, and in this case stands for "INternet".
The "A" tells the DNS that this is an Address (as opposed to a mail server, alias, or whatever)
The "192.168.5.100" is the IP (Internet Protocol) of the server.
Altogether, this line tells anyone who asks that the domain name www.mcanerin.com is an internet address that you can find at the IP address of 192.168.5.100.

Now, what would happen if I made another line in this DNS so it looked like:

www.mcanerin.com IN A 192.168.5.100

mcanerin.com IN A 192.168.5.100

This would now point BOTH of these names at the same address. Otherwise, if someone typed in "mcanerin.com" without the "www" the DNS server would not know what to do and the user would get a dead page. Most web hosts automatically add both versions to your DNS because this is a common problem.

But a search engine would consider this to be 2 separate websites, at least at first. Why? Because although it's common for people to be lazy and not type in the "www", you can actually set things up so that these point to 2 separate servers. In the old days, servers were not very powerful, so it was common to have separate servers do separate jobs. You could have a firewall called mcanerin.com, a webserver called www.mcanerin.com, an ftp server called ftp.mcanerin.com, a mail server called mail.mcanerin.com, and so on. Each of these would be separate servers with their own IP addresses.

So a search engine (unlike many of today's casual internet users) can't just assume that mcanerin.com and www.mcanerin.com are the same site - not everyone has a powerful server. Many companies are running legacy systems set up back in the old days, and even today some people in third world countries are getting by with servers that are old and slow.

At first, the search engine will treat the two domains as two separate sites, but will eventually (once it's fully indexed both for some time) figure out that they are the same, and then merge the data for the two, which can take up to a year. In the meantime, any links that you have going to mcanerin.com would not be credited to www.mcanerin.com. For a while when I first launched my website, mcanerin.com had a PR of 2 and 9 backlinks on Google, but www.mcanerin.com had a PR of 4 with 46 backlinks showing. Eventually (it took a long time), the data merged and I ended up with a PR of 5 with 55 backlinks showing. This obviously has SEO issues, since usually you want to get credit for all your backlinks as soon as possible.

So eventually (once they figure it out) the search engine is treating both addresses as belonging to the same website. This is domain parking in a nutshell from an SEO perspective. You are pointing 2 (or more) domains at the same website.

Now, lets add another domain to the mix:

www.mcanerin.com IN A 192.168.5.100

mcanerin.com IN A 192.168.5.100

mcanerin.ca IN A 192.168.5.100

You will notice that this is the Canadian ccTLD (country code Top Level Domain). If we add this to the mix you will find that the search engines will now also associate the .ca domain to the website, and therefore treat it as a Canadian website, which is good because the Canadian versions of the major search engines give preference (and a ranking bonus) to Canadian sites. The same applies to other areas, such as the UK, China, Australia and so forth.

In general, unless you are attempting to attach a ccTLD to an existing .com/net/org site for the purposes of geolocation, I do not recommend parking for SEO purposes, for 2 reasons:

The effect of your links (and PageRank) being split between the two sites
The fact that the second site will be considered a duplicate, and possibly trip an anti-spam filter if you have enough parks
The only time I recommend parking is for geolocation purposes. The above two reasons eventually disappear when the search engine figures things out, so it's a temporary problem, usually. Yahoo is very well known for not liking multiple domains, though, so I like to be very careful with parks.