Certain phones numbers can prove to be quite beneficial for businesses. As opposed to a normal land line or mobile number, 0800 numbers or other non geographic numbers can sound more professional, project a bigger image, and all of these numbers have their own unique advantages.
An 0800 number is usually free for callers on most phone services. An 0800 number projects a nationwide image, one which a local landline number never could. It doesn't matter that the call is eventually routed to your tiny handset in your modest office, the point is, if you're offering a competent product or service, you don't want to lose out on clients only because of your location!
Not all non geographic numbers are free to call, and some cost significantly more than others. Businesses use these numbers to manage their customer service costs so that calls to some services cost more than calls to, say initial enquiries.
Apart from providing different options in terms of numbers, these numbers can also be diverted to other numbers. This can be particularly beneficial to people that travel a lot and need to have a constant number that callers can call, that can be routed to different numbers.
In a world dominated by electronics and technology, the image of a company is made not only by the service it provides, but by several other determining factors.