Lately we have received a few questions at Pure Visibility about whether or not a company should buy multiple domain names/extensions and how many variations of their company name is enough. Unfortunately, there is not one simple answer to this question and it really depends on the company. Most of the time we do recommend to buy not only your company URL, but to get common misspellings and alternative names that a potential customer might use to find your company. As far as purchasing multiple extensions such as the .org, .net and .mobi we typically don’t recommend doing so unless you have a good reason for it. A good example of a company purchasing multiple domain extensions is USAJobs whose main domain extension is .gov They also purchased usajobs.com; clearly they learned from the whitehouse.com vs. whitehouse.gov debacle.
I recently talked to a client who was informed that a competitor was interested in buying their company name with the .net extension. The law can be a little unclear about whether you can buy any url if it has a trademarked name in it, so, the client was considering just buying the other extension to avoid legal headaches (see avoiding copyright infringment on your domain name for more details.) I concurred that it was logical to buy the .net to avoid headaches, but also told them to rest assured that they don’t have to purchase every extension out there.
The important next step is to not make a duplicate site at the .net address, rather, set up a 301 redirect. If you simply make a clone of your site you will risk being marked as spam by Google and getting de-indexed. How to redirect parked domains.
I also had a client contact us about the .mobi extension in particular. They were informed that .mobi was the up and coming URL for mobile devices and thought it would be a good idea to buy this extension before a competitor could beat them to it. We decided that for them it would be a better idea not to buy the .mobi extension because, if they wanted their site to be visible on a cell phone browser they could edit their current site design to be mobile friendly (make your site mobile friendly.) I believe that you don’t need to purchase the .mobi extension until it becomes more popular, currently someone using a mobile browser would typically type in .com because it is the most familiar but this could change in the future.
The rule of thumb I use when buying domain extensions is make sure I have the .com and if I have a compelling reason to purchase additional extensions then I do it. If there is reason to believe a competitor might purchase my url with a different extension then I spend the small amount of money ($5.00-$30.00/year) it takes to buy the additional domains