BT Internet is added to your phonebill, BT Openworld is a completely seperate company...
Theyre both able to offer you the same packages for the same prices (i think) They both have seperate tech support numbers etc..... I dont know why they bothered...... but they obviously thought it was a good idea....
They may have originally set BTOpenWorld up for Residential And BT Internet for business i suppose.... but your able to get either for either.... so....
Maybe someone else can shed some light on this?