Multiple identifiers for user accounts

1. A computer-implemented method for assigning multiple identifiers to user accounts, the method being performed by at least one processor, the method comprising:

receiving, at a server, an indication of an event on a client device;

associating the event with a user;

associating the user with at least a first account identifier of a plurality of accounts, on a plurality of applications, of the user;

associating the user with at least a second account identifier of the plurality of accounts of the user, the second account identifier different than the first account identifier, and wherein at least one of the first account identifier and the second account identifier comprises a hard matched identifier;

adding at least one of the first account identifier or the second account identifier to a custom audience relating to the event, wherein the event is separately stored in an advertisement delivery system in association with features of the plurality of accounts;

targeting the custom audience through directed advertising; and

delivering, to the client device, advertisements to the custom audience via one or more of the plurality of accounts based on the advertisement delivery system.

2. The computer-implemented method of claim 1 , wherein the event comprises a pixel event.

3. The computer-implemented method of claim 1 , wherein the account identifier comprises a soft matched identifier.

4. The computer-implemented method of claim 1 , wherein the event comprises an onsite event or an offsite event.

5. The computer-implemented method of claim 1 , wherein the plurality of accounts are from a family of accounts.

6. The computer-implemented method of claim 1 , wherein associating the event with the user comprises:

sending a request for determining a best candidate.

7. The computer-implemented method of claim 6 , further comprising:

receiving the determination of the best candidate.

8. The computer-implemented method of claim 1 , wherein the account identifier comprises a first type identifier or a second type identifier.

9. The computer-implemented method of claim 8 , wherein both the first type identifier and the second type identifier comprise first-class citizens.

10. A system configured for assigning multiple identifiers to user accounts, the system comprising:

one or more hardware processors configured by machine-readable instructions to:

receive, at a server, an indication of an event on a client device;

associate the event with a user;

associate the user with at least a first account identifier of a plurality of accounts, on a plurality of applications, of the user;

associate the user with at least a second account identifier of the plurality of accounts of the user, the second account identifier different than the first account identifier, and wherein at least one of the first account identifier and the second account identifier comprises a hard matched identifier;

add at least one of the first account identifier or the second account identifier to a custom audience relating to the event, wherein the event is separately stored in an advertisement delivery system in association with features of the plurality of accounts;

target the custom audience through directed advertising; and

deliver, to the client device, advertisements to the custom audience via one or more of the plurality of accounts based on the advertisement delivery system.

11. The system of claim 10 , wherein the event comprises a pixel event.

12. The system of claim 10 , wherein the account identifier comprises a soft matched identifier.

13. The system of claim 10 , wherein the event comprises an onsite event or an offsite event.

14. The system of claim 10 , wherein the plurality of accounts are from a family of accounts.

15. The system of claim 10 , wherein the one or more hardware processors are further configured by machine-readable instructions to:

send a request for determining a best candidate.

16. The system of claim 15 , wherein the one or more hardware processors are further configured by machine-readable instructions to:

receive the determination of the best candidate.

17. The system of claim 10 , wherein the account identifier comprises a first type identifier or a second type identifier.

18. A non-transient computer-readable storage medium having instructions embodied thereon, the instructions being executable by one or more processors to perform a method for assigning multiple identifiers to user accounts, the method comprising:

receiving, at a server, an indication of an event on a client device;

associating the event with a user;

associating the user with at least a first account identifier of a plurality of accounts, on a plurality of applications, of the user;

associating the user with at least a second account identifier of the plurality of accounts of the user, the second account identifier different than the first account identifier, and wherein at least one of the first account identifier and the second account identifier comprises a hard matched identifier;

adding at least one of the first account identifier or the second account identifier to a custom audience relating to the event, wherein the event is separately stored in an advertisement delivery system in association with features of the plurality of accounts;

targeting the custom audience through directed advertising; and

delivering, to the client device, advertisements to the custom audience via one or more of the plurality of accounts based on the advertisement delivery system.