Ranking of address book contacts based on social proximity

1. A method comprising:

by one or more computing devices, accessing a contacts list comprising one or more contacts in an address book of a first user;

by one or more computing devices, accessing a data store for existing social-graph information between each contact in the contacts list and the first user;

by one or more computing devices, accessing communication-history information for each contact in the contacts list, the communication-history information for a contact indicating a frequency of communication between the first user and the contact;

by one or more computing devices, determining a usage frequency for each of one or more communication channels for each contact in the contacts list based on the communication-history information;

by one or more computing devices, determining a social-proximity score for each contact in the contacts list based at least in part on the social-graph information, weighted average of the usage frequency of each of the communication channels, and one or more user-declared relationship types between the first user and other contacts of the contacts list;

by one or more computing devices, ranking the contacts in the contacts list based at least in part on the social-proximity scores; and

by one or more computing devices, providing the contacts list for display with the contacts as ranked based at least in part on the social proximity scores.

2. The method of claim 1 , wherein the social-graph information comprises a degree-of-separation coefficient for each contact in the contacts list with respect to the first user.

3. The method of claim 1 , wherein the social-graph information comprises an affiliation coefficient for each contact in the contacts list with respect to the first user.

4. The method of claim 1 , wherein accessing the communication-history information for each contact in the contacts list comprises:

accessing a data store of communication history.

5. The method of claim 1 , wherein:

the social-graph information comprises:

a degree-of-separation coefficient for each contact in the contacts list with respect to the first user; and

an affiliation coefficient for each contact in the contacts list with respect to the first user;

the method comprises:

accessing a data store of communication history; and

accessing a weighting factor for each of the communication channels; and

wherein the social-proximity score for each contact in the contacts list is based on a summation of the degree-of-separation coefficient, the affiliation coefficient, and the weighted average of the usage frequency of the communication channels, wherein the weighted average is calculated with the weighting factor for each of the communication channels.

6. A system comprising:

one or more processors; and

a memory coupled to the processors comprising instructions executable by the processors, the processors being operable when executing the instructions to:

access a contacts list comprising one or more contacts in an address book of a first user;

access a data store for existing social-graph information between each contact in the contacts list and the first user;

access communication-history information for each contact in the contacts list, the communication-history information for a contact indicating a frequency of communication between the first user and the contact;

determine a usage frequency for each of one or more communication channels for each contact in the contacts list based on the communication-history information;

determine a social-proximity score for each contact in the contacts list based at least in part on the social-graph information, a weighted average of the usage frequency of each of the communication channels, and one or more user-declared relationship types between the first user and other contacts of the contacts list;

rank the contacts in the contacts list based at least in part on the social-proximity scores; and

provide the contacts list for display with the contacts as ranked based at least in part on the social proximity scores.

7. The system of claim 6 , wherein the social-graph information comprises a degree-of-separation coefficient for each contact in the contacts list with respect to the first user.

8. The system of claim 6 , wherein the social-graph information comprises an affiliation coefficient for each contact in the contacts list with respect to the first user.

9. The system of claim 6 , wherein accessing the communication-history information for each contact in the contacts list comprises:

accessing a data store of communication history.

10. The system of claim 6 , wherein:

the social-graph information comprises:

a degree-of-separation coefficient for each contact in the contacts list with respect to the first user; and

an affiliation coefficient for each contact in the contacts list with respect to the first user;

the processors are operable when executing the instructions to:

access a data store of communication history; and

access a weighting factor for each of the communication channels; and

wherein the social-proximity score for each contact in the contacts list is based on a summation of the degree-of-separation coefficient, the affiliation coefficient, and the weighted average of the usage frequency of the communication channels, wherein the weighted average is calculated with the weighting factor for each of the communication channels.

11. One or more computer-readable non-transitory storage media embodying software that is operable when executed to:

access a contacts list comprising one or more contacts in an address book of a first user;

access a data store for existing social-graph information between each contact in the contacts list and the first user;

access communication-history information for each contact in the contacts list, the communication-history information for a contact indicating a frequency of communication between the first user and the contact;

determine a usage frequency for each of one or more communication channels for each contact in the contacts list based on the communication-history information;

determine a social-proximity score for each contact in the contacts list based at least in part on the social-graph information, a weighted average of the usage frequency of each of the communication channels, and one or more user-declared relationship types between the first user and other contacts of the contacts list;

rank the contacts in the contacts list based at least in part on the social-proximity scores; and

provide the contacts list for display with the contacts as ranked based at least in part on the social proximity scores.

12. The media of claim 11 , wherein the social-graph information comprises a degree-of-separation coefficient for each contact in the contacts list with respect to the first user.

13. The media of claim 11 , wherein the social-graph information comprises an affiliation coefficient for each contact in the contacts list with respect to the first user.

14. The media of claim 11 , wherein accessing the communication-history information for each contact in the contacts list comprises:

accessing a data store of communication history.

15. The media of claim 11 , wherein:

the social-graph information comprises:

a degree-of-separation coefficient for each contact in the contacts list with respect to the first user; and

an affiliation coefficient for each contact in the contacts list with respect to the first user;

the software is operable when executed to:

access a data store of communication history; and

access a weighting factor for each of the communication channels; and

wherein the social-proximity score for each contact in the contacts list is based on a summation of the degree-of-separation coefficient, the affiliation coefficient, and the weighted average of the usage frequency of the communication channels, wherein the weighted average is calculated with the weighting factor for each of the communication channels.