Maybe you have been tempted to buy more than one domain name for your web presence, although this most probably will not lead to increase your Search Engine Rank, it could be helpful for other reasons.
One of these reasons could be protecting your brand, if you own wsinetsense.com you might want to buy wsinetsense.net and maybe wsi-netsense.com or even wsi-net-sense.com to prevent others from building their website on your successful brand that you have worked hard to build.
Another reason could be getting similar names that your clients could type in by mistake when trying to get to your site like wsiwebsense.com using web instead of net. Also buying a misspelled version of your domain could be a good addition to your multiple domain selection, like wsinetsence.com, or wsinetcense.com both of these techniques will provide you with a way to catch clients that didn’t get the name right, forgot the exact name, or typed it wrong.
Also, getting a domain name for a specific local area or a specific industry could be a good option if you think it will stick to your clients’ mind better or it will give you an edge over your competitors. An example would be if you are targeting clients in a specific geographic area, you could add that area name in front of your domain and use that domain name in the marketing material in that area, like if we are only targeting the bay area we can buy BayAreaWsiNetSense.com or if you are in the limousine business and your domain name is LimoServices.com you might want to get SanJoseLimoServices.com to target the local clients. The same is true if you are targeting a specific industry where you can use the name of the industry in your domain name to let your client know that you are specialized in that industry, as an example we can use WSINetTravelsense.com if we are targeting the travel industry.
Finally, getting a similar domain for a specific use or purpose is also a valid option, this specific use could be a support site, a store website, a discussion group site, or even for a separate blog