Nearby Friend Notifications on Online Social Networks

1 . A method comprising, by one or more computing systems:

receiving an indication of a first location of a first mobile-client system of a first user associated with an online social network;

identifying one or more second users from among a plurality of users associated with the online social network based on one or more notification rules, wherein each identified second user is associated with a second mobile-client system having a second location within a threshold distance of the first location, and wherein each identified second user is within a threshold degree of separation of the first user on the online social network; and

sending a first notification to the first mobile-client system of the first user, the first notification referencing one or more of the identified second users.

2 . The method of claim 1 , further comprising receiving, for each of one or more of the second users, an indication of the second location of the second mobile-client system of the second user.

3 . The method of claim 1 , further comprising receiving a request by the first user to send a second notification referencing the first user, the first location, and a content item to the one or more second users of the online social network, wherein:

the content item comprises one or more of a text, a photo, a video, an audio recording, a status update, or a message.

4 . The method of claim 3 , further comprising, in response to the request by the first user, for each of one or more of the second users, sending the second notification to the second mobile-client system associated with the second user.

5 . The method of claim 1 , wherein identifying the one or more second users from among the plurality of users is further based on an affinity coefficient between the first user and the second users.

6 . The method of claim 1 , wherein the first notification comprises one or more of a SMS message, a MMS message, an email message, a banner notification, a pop-up notification, an in-app notification, or a cloud-to-device notification.

7 . The method of claim 1 , wherein the first notification is automatically sent to the first mobile-client of the first user responsive to the one or more notification rules being satisfied.

8 . The method of claim 1 , further comprising generating a location history associated with the first user or the second user, the location history comprising, for each user:

one or more geographic locations associated with the user; and

one or more time stamps corresponding to each of the geographic locations.

9 . The method of claim 8 , wherein the location history is updated based on check-in activities of the first user or the second user.

10 . The method of claim 1 , wherein the one or more notification rules comprise refraining from sending the first notification if one or more of:

the first location or the second location is a hotspot associated with the first user or the second user, respectively;

the first location or the second location is stationary for at least a predetermined time period;

a social closeness of the first user with respect to the second user exceeds a threshold value;

a previous notification referencing the second user was sent to the first user within a threshold previous time period;

the first user and second user were recorded as being at the same location within a threshold previous time period;

the first location or the second location is not accurately determined; or

the first user is determined to be already aware that the second user is nearby.

11 . The method of claim 10 , wherein the first notification is sent if a predetermined number of the notification rules are satisfied.

12 . The method of claim 10 , wherein the first user and the second user were recorded as being at the same location within the threshold previous time period based on a comparison of a location history associated with the first user with a location history associated with the second user.

13 . The method of claim 10 , wherein the first location of the first user or the second location of the second user is not accurately determined if a location history associated with the first user or a location history associated with the second user does not have a time stamp associated with a geographic location within the threshold previous time period.

14 . The method of claim 10 , wherein the first user is determined to be already aware that the second user is nearby based on a comparison of a location history associated with the first user with a location history associated with the second user.

15 . The method of claim 10 , wherein the first user is determined to be already aware that the second user is nearby based on a communication between the first user and the second user.

16 . The method of claim 1 , wherein the first notification further specifies a distance of each referenced second user from the first user.

17 . The method of claim 1 , wherein the first notification is sent to the first user for presentation in a list comprising at least one notification, wherein the list is ordered based on one or more of:

a distance of each referenced second user from the first user; or

a time that each notification was sent to the first user.

18 . The method of claim 1 , wherein the first location is based on one or more of a global position system (GPS) signal, a Wi-Fi signal, or a cellular radio signal.

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

receive an indication of a first location of a first mobile-client system of a first user associated with an online social network;

identify one or more second users from among a plurality of users associated with the online social network based on one or more notification rules, wherein each identified second user is associated with a second mobile-client system having a second location within a threshold distance of the first location, and wherein each identified second user is within a threshold degree of separation of the first user on the online social network; and

send a first notification to the first mobile-client system of the first user, the first notification referencing one or more of the identified second users.

20 . A system comprising: one or more processors; and a memory coupled to the processors comprising instructions executable by the processors, the processors operable when executing the instructions to:

receive an indication of a first location of a first mobile-client system of a first user associated with an online social network;

identify one or more second users from among a plurality of users associated with the online social network based on one or more notification rules, wherein each identified second user is associated with a second mobile-client system having a second location within a threshold distance of the first location, and wherein each identified second user is within a threshold degree of separation of the first user on the online social network; and

send a first notification to the first mobile-client system of the first user, the first notification referencing one or more of the identified second users.