It happens all the time, and causes me to scratch my head in complete confusion every time: Someone I'm working with on SEO will own multiple domains for the same business. I don't mean that they have a couple related domains, I mean the same business and same offerings or services on more than one domain.
I usually find out about these domains in one of two ways: I find them through poking around and investigating the site (and the client usually acts like it's some sort of dirty secret), or, they come to me about the domains and want more than one site to show up at the top of the search results.
I'll be honest, I'm not usually a happy camper when I get this news; mostly because the secondary domains tend to have duplicate content (if you're not aware, duplicate content is a bad thing). That being said, however, there is such thing as effectively using multiple domains (although I don't recommend it). There are two main tactics commonly employed with owning multiple domains. Keep in mind that I'm going to keep an SEO perspective on these and only lightly touch on other marketing sectors.
The Defensive Domain Buyer
Some businesses are worried that competitors will buy keyword oriented domains thereby pushing their own site into obscurity. This can lead to a panic shopping spree of domains. The idea is that as long as they own the available domains, there is less chance of a competitor beating them in the rankings. While there is some merit to this tactic, it will have no effect on your SEO at all. Nor do I believe that it will really have much effect in blocking out your competitors. You can't think of all the domain variations and buy them all, and if you buy too many, it can get expensive just to maintain them. Any competitor can rank better by offering better content and getting more links regardless of domain name.
As a side note, if you do this tactic, you had better make sure that all of your domains are redirected toward your main domain using a 301 redirect.
The First Page Domination Strategy
In buying multiple domains, some companies want to simply dominate the search results. Buy having multiple sites on the first page, you can get that much more traffic, right? In theory, yes, and it has on occasion happened. However, there are some fairly serious drawbacks to this:
- Doesn't work on brick-and-mortar stores -- If you have a single physical location, it's not a good idea to have multiple websites. You'll confuse your visitors and customers, and I personally avoid having two websites with the same address. Google doesn't want to have multiple sites from the same business (as it doesn't provide good results) and I consider this to be one short step away from spam.
- Duplicate content woes -- Because you can't use the content from another site, you will have to write all new content. Considering how hard it is to write content for sites as it is, not to mention the allocation of resources to get it written, I wish luck to anyone writing content for a whole new site.
- Double branding all the way! -- You have branding issues with two sites. Does one site become higher-end and the lower-end? Do you keep the prices the same? For that matter, what names are you even going to use on the site? If you have a phone number, how do you answer the phone? While there are certainly going to be exceptions (such as targeting different demographics), such a chaotic and divisive branding effort comes with a lot of risks and extra work.
Country Specific Domains
This is less of a tactic, and more of a "must do," and is therefore my exception to multiple domains. It's an exception because all of the problems above do not apply when you get into other countries. In fact, in order to have the best results in international SEO, you'll need to have a country specific TLD (or top level domain). For example, if you're doing business in England, you will have a hard time ranking without a .co.uk domain. You can still rank without a country level TLD, but it's an uphill battle. And by uphill, I mean Rocky Mountains-type uphill.
SEO Resources and Indented Listings
One final (and big) point to that I would like to reiterate. If you really intend to own and run multiple domains and get these sites to show up in the search results, you will have to double your SEO work. There are no shortcuts, freebies, or quick rankings that you can get, even if you are already ranking well for your main domain. In fact, a new domain and site will be significantly harder to rank than a site that has history and some authority already built. I highly recommend that indented listings (or secondary pages for the same site showing up underneath the first main listing) be the primary goal before attempting to achieve multiple domains in the same search.