Which extension to choose?
The extension is a point of refernce as in it's choice depends heavily on the site it represents. There is no need to order one .com, one.net or one .biz. for the same site. Each extension underlies a brand, a business segment, geographic area, target audience etc. and it must be best adapted to the activity on the site.
Brand awareness and protection of the site
The more a brand is recognised, the more the domain name attached to it is wanted by competitors, typosquatters and cybersquatters. Preserving a trademark and domain name is gaining in value (eg.: mybiz.com). Therefore, it is often necessary to register the same domain with different GTLD extensions (eg mybiz.com, mybiz.net, mybiz.biz, etc..). Most importantly, you need to make sure that they are available to register. Don't waste time later. Just simply and quickly check the availability now!
Nationalised extensions (ccTLDs) such as .ie or .fr often include registration restrictions. To get a domain with these extensions, certain requirements must be met!
Many extensions are characteristic of specific areas of activity such as, .tel, .fm., .mobi., .pro, etc... Having a specific extension domain that is relevant to your business reinforces the professionalism of your site.
The choice of extension must be made according to regions and countries where the site and the activity are represented. The geographic origin of visitors and the catchment area of the site are critical. National and international border extensions are available.