Methods and apparatus to share online media impressions data

1. An apparatus, comprising:

communications interface circuitry; and

a web browser to:

send a first request to an audience measurement entity via the communications interface circuitry; and

send a second request via the communications interface circuitry to cause a database proprietor to send to the audience measurement entity a uniform resource locator including a value of an audience measurement entity cookie and a value of a database proprietor cookie as a cookie mapping of the audience measurement entity cookie to the database proprietor cookie, the audience measurement entity cookie and the database proprietor cookie corresponding to a client device, the audience measurement entity cookie corresponding to a first domain, the database proprietor cookie corresponding to a second domain.

2. An apparatus as defined in claim 1 , wherein the web browser is to send the audience measurement entity cookie in the first request.

3. An apparatus as defined in claim 1 , wherein the web browser is to send the first request to the audience measurement entity in response to executing beacon instructions in a web page.

4. An apparatus as defined in claim 1 , wherein the second request is further to cause the database proprietor to send to the audience measurement entity a demographic characteristic associated with the client device.

5. An apparatus as defined in claim 1 , wherein the web browser is to:

send a third request to the audience measurement entity; and

send a fourth request to a second database proprietor to cause the second database proprietor to send to the audience measurement entity a second cookie mapping of the audience measurement entity cookie to a second database proprietor cookie.

6. An apparatus as defined in claim 1 , wherein the second request is to cause the database proprietor to send the cookie mapping to the audience measurement entity asynchronously.

7. An apparatus as defined in claim 1 , wherein the web browser is to send a third request to the audience measurement entity, the third request including the cookie mapping.

8. A computer readable storage medium comprising computer readable instructions which, when executed, cause a client device to at least:

send a first request to an audience measurement entity; and

send a second request to cause a database proprietor to send to the audience measurement entity a uniform resource locator including a value of an audience measurement entity cookie and a value of a database proprietor cookie as a cookie mapping of the audience measurement entity cookie to the database proprietor cookie, the audience measurement entity cookie and the database proprietor cookie corresponding to the client device, the audience measurement entity cookie corresponding to a first domain, the database proprietor cookie corresponding to a second domain.

9. A storage medium as defined in claim 8 , wherein the instructions are further to cause the client device to store the database proprietor cookie.

10. A storage medium as defined in claim 8 , wherein the instructions are to cause the client device to send the first request to the audience measurement entity in response to executing beacon instructions in a web page.

11. A storage medium as defined in claim 8 , wherein the second request is further to cause the database proprietor to send to the audience measurement entity a demographic characteristic associated with the client device.

12. A storage medium as defined in claim 8 , wherein the instructions are further to cause the client device to:

send a third request to the audience measurement entity; and

send a fourth request to cause a second database proprietor to send to the audience measurement entity a second cookie mapping of the audience measurement entity cookie to a second database proprietor cookie.

13. A storage medium as defined in claim 8 , wherein the instructions are further to cause the client device to send a third request to the audience measurement entity, the third request including the cookie mapping.

14. A method comprising:

sending, from a client device, a first request to an audience measurement entity; and

sending, from the client device, a second request to cause a database proprietor to send to the audience measurement entity a uniform resource locator including a value of an audience measurement entity cookie and a value of a database proprietor cookie as a cookie mapping of the audience measurement entity cookie to the database proprietor cookie, the audience measurement entity cookie and the database proprietor cookie corresponding to the client device, the audience measurement entity cookie corresponding to a first domain, the database proprietor cookie corresponding to a second domain.

15. A method as defined in claim 14 , further including storing the database proprietor cookie.

16. A method as defined in claim 14 , wherein sending the first request to the audience measurement entity is in response to executing beacon instructions in a web page.

17. A method as defined in claim 14 , wherein the second request is further to cause the database proprietor to send to the audience measurement entity a demographic characteristic associated with the client device.

18. A method as defined in claim 14 , further including:

sending a third request to the audience measurement entity; and

sending a fourth request to cause a second database proprietor to send to the audience measurement entity a second cookie mapping of the audience measurement entity cookie to a second database proprietor cookie.

19. A method as defined in claim 14 , wherein the second request is to cause the database proprietor to send the cookie mapping to the audience measurement entity asynchronously.

20. A method as defined in claim 14 , further including sending a third request to the audience measurement entity, the third request including the cookie mapping.

21. An apparatus as defined in claim 1 , further including receive a re-direct message from the audience measurement entity, the re-direct message including an identifier of an audience measurement entity cookie.