1. A method performed by a social network system accessible over a data network with a plurality of data input devices connectable to said data network, said social network system including a plurality of entity data records each relating to a corresponding user entity and containing one or more entity attributes including at least one identifying characteristic of said corresponding user entity, said method including providing, via said data network, a given user entity with: a virtual, unique, personal, social network (hereinafter ‘social network’) formed from connections between contacts, said contacts including other user entities connected directly or indirectly to said given user entity; respective interrelationship context information including: details of any common entity attributes, and/or a connection factor, between two contacts and/or between a contact and the given user entity; access to at least part of at least one the entity data records; the option to take a role in a predetermined activity and/or application via said data network, wherein said role includes at least one of provider or participant, wherein a provider is a user entity providing an item or service to at least one other user entity; and a participant is a user entity utilising said provider's item or service.