...landline use the incumbent as their main supplier. And although one in four businesses have changed fixed line telephonesupplier, a significant amount of these actually changed back to the original provider. "The results of the eBusiness...
http://www.theregister.co.uk/2007/07/19/chambers_ebusiness_survey/
...one assigned by a supplier. Avoid the unpleasant prospect of changing your product literature if you change your telephonesupplier. If for some reason you can't provide an 800 number, we will assign you one, and make an assignment to you...
http://www.hudsonsoft.com/pages/ts_ts3.htm